scholarly journals Effects of Sequential and Simultaneous Applications of Bacteriophages on Populations of Pseudomonas aeruginosaIn Vitroand in Wax Moth Larvae

2012 ◽  
Vol 78 (16) ◽  
pp. 5646-5652 ◽  
Author(s):  
Alex R. Hall ◽  
Daniel De Vos ◽  
Ville-Petri Friman ◽  
Jean-Paul Pirnay ◽  
Angus Buckling
Keyword(s):  
Bacterial Infections ◽  
Phage Therapy ◽  
Phage Type ◽  
Resistant Bacteria ◽  
Short Term ◽  
Short Term Treatment ◽  
Simultaneous Application ◽  
Content Type ◽  
Wax Moth

ABSTRACTInterest in using bacteriophages to treat bacterial infections (phage therapy) is growing, but there have been few experiments comparing the effects of different treatment strategies on both bacterial densities and resistance evolution. While it is established that multiphage therapy is typically more effective than the application of a single phage type, it is not clear if it is best to apply phages simultaneously or sequentially. We tried single- and multiphage therapy againstPseudomonas aeruginosaPAO1in vitro, using different combinations of phages either simultaneously or sequentially. Across different phage combinations, simultaneous application was consistently equal or superior to sequential application in terms of reducing bacterial population density, and there was no difference (on average) in terms of minimizing resistance. Phage-resistant bacteria emerged in all experimental treatments and incurred significant fitness costs, expressed as reduced growth rate in the absence of phages. Finally, phage therapy increased the life span of wax moth larvae infected withP. aeruginosa, and a phage cocktail was the most effective short-term treatment. When the ratio of phages to bacteria was very high, phage cocktails cured otherwise lethal infections. These results suggest that while adding all available phages simultaneously tends to be the most successful short-term strategy, there are sequential strategies that are equally effective and potentially better over longer time scales.

scholarly journals Mutant and Recombinant Phages Selected from In Vitro Coevolution Conditions Overcome Phage-Resistant Listeria monocytogenes

2020 ◽  
Vol 86 (22) ◽  
Author(s):  
Tracey Lee Peters ◽  
Yaxiong Song ◽  
Daniel W. Bryan ◽  
Lauren K. Hudson ◽  
Thomas G. Denes
Keyword(s):  
Listeria Monocytogenes ◽  
Host Range ◽  
Foodborne Pathogen ◽  
Resistant Bacteria ◽  
Phage Resistance ◽  
Short Term ◽  
Content Type ◽  
Life Threatening ◽  
The Impact

ABSTRACT Bacteriophages (phages) are currently available for use by the food industry to control the foodborne pathogen Listeria monocytogenes. Although phage biocontrols are effective under specific conditions, their use can select for phage-resistant bacteria that repopulate phage-treated environments. Here, we performed short-term coevolution experiments to investigate the impact of single phages and a two-phage cocktail on the regrowth of phage-resistant L. monocytogenes and the adaptation of the phages to overcome this resistance. We used whole-genome sequencing to identify mutations in the target host that confer phage resistance and in the phages that alter host range. We found that infections with Listeria phages LP-048, LP-125, or a combination of both select for different populations of phage-resistant L. monocytogenes bacteria with different regrowth times. Phages isolated from the end of the coevolution experiments were found to have gained the ability to infect phage-resistant mutants of L. monocytogenes and L. monocytogenes strains previously found to be broadly resistant to phage infection. Phages isolated from coinfected cultures were identified as recombinants of LP-048 and LP-125. Interestingly, recombination events occurred twice independently in a locus encoding two proteins putatively involved in DNA binding. We show that short-term coevolution of phages and their hosts can be utilized to obtain mutant and recombinant phages with adapted host ranges. These laboratory-evolved phages may be useful for limiting the emergence of phage resistance and for targeting strains that show general resistance to wild-type (WT) phages. IMPORTANCE Listeria monocytogenes is a life-threatening bacterial foodborne pathogen that can persist in food processing facilities for years. Phages can be used to control L. monocytogenes in food production, but phage-resistant bacterial subpopulations can regrow in phage-treated environments. Coevolution experiments were conducted on a Listeria phage-host system to provide insight into the genetic variation that emerges in both the phage and bacterial host under reciprocal selective pressure. As expected, mutations were identified in both phage and host, but additionally, recombination events were shown to have repeatedly occurred between closely related phages that coinfected L. monocytogenes. This study demonstrates that in vitro evolution of phages can be utilized to expand the host range and improve the long-term efficacy of phage-based control of L. monocytogenes. This approach may also be applied to other phage-host systems for applications in biocontrol, detection, and phage therapy.

scholarly journals Evolution of Pseudomonas aeruginosa Virulence as a Result of Phage Predation

2013 ◽  
Vol 79 (19) ◽  
pp. 6110-6116 ◽  
Author(s):  
Zeinab Hosseinidoust ◽  
Theo G. M. van de Ven ◽  
Nathalie Tufenkji
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Mammalian Cells ◽  
Bacterial Infections ◽  
Membrane Damage ◽  
Human Keratinocytes ◽  
Host Population ◽  
Resistant Bacteria ◽  
Content Type ◽  
Metabolic Action

ABSTRACTThe rapid increase in the emergence of antibiotic-resistant bacteria has attracted attention to bacteriophages for treating and preventing bacterial infections. Bacteriophages can drive the diversification ofPseudomonas aeruginosa, giving rise to phage-resistant variants with different phenotypes from their ancestral hosts. In this study, we sought to investigate the effect of phage resistance on cytotoxicity of host populations toward cultured mammalian cells. The library of phage-resistantP. aeruginosaPAO1 variants used was developed previously via experimental evolution of an isogenic host population using phages PP7 and E79. Our results presented herein indicate that the phage-resistant variants developed in a heterogeneous phage environment exhibit a greater ability to impede metabolic action of cultured human keratinocytes and have a greater tendency to cause membrane damage even though they cannot invade the cells in large numbers. They also show a heightened resistance to phagocytosis by model murine macrophages. Furthermore, all isolates produced higher levels of at least one of the secreted virulence factors, namely, total proteases, elastase, phospholipase C, and hemolysins. Reverse transcription-quantitative PCR (RT-qPCR) revealed upregulation in the transcription of a number of genes associated with virulence ofP. aeruginosafor the phage-resistant variants. The results of this study indicate a significant change in thein vitrovirulence ofP. aeruginosafollowing phage predation and highlight the need for caution in the selection and design of phages and phage cocktails for therapeutic use.

scholarly journals Analyses of Short-Term Antagonistic Evolution of Pseudomonas aeruginosa Strain PAO1 and Phage KPP22 (Myoviridae Family, PB1-Like Virus Genus)

2016 ◽  
Vol 82 (15) ◽  
pp. 4482-4491 ◽  
Author(s):  
Jumpei Uchiyama ◽  
Masato Suzuki ◽  
Koji Nishifuji ◽  
Shin-ichiro Kato ◽  
Reina Miyata ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Bacterial Resistance ◽  
Phage Therapy ◽  
Open Reading Frames ◽  
Missense Mutations ◽  
Short Term ◽  
Strain Pao1 ◽  
Content Type ◽  
Phage Adsorption

ABSTRACTPseudomonas aeruginosacauses serious intractable infections in humans and animals. Bacteriophage (phage) therapy has been applied to treatP. aeruginosainfections, and phages belonging to the PB1-like virus genus in theMyoviridaefamily have been used as therapeutic phages. To achieve safer and more effective phage therapy, the use of preadapted phages is proposed. To understand in detail such phage preadaptation, the short-term antagonistic evolution of bacteria and phages should be studied. In this study, the short-term antagonistic evolution of bacteria and PB1-like phage was examined by studying phage-resistant clones ofP. aeruginosastrain PAO1 and mutant PB1-like phages that had recovered their infectivity. First, phage KPP22 was isolated and characterized; it was classified as belonging to the PB1-like virus genus in theMyoviridaefamily. Subsequently, three KPP22-resistant PAO1 clones and three KPP22 mutant phages capable of infecting these clones were isolated in three sets ofin vitroexperiments. It was shown that the bacterial resistance to phage KPP22 was caused by significant decreases in phage adsorption and that the improved infectivity of KPP22 mutant phages was caused by significant increases in phage adsorption. The KPP22-resistant PAO1 clones and the KPP22 mutant phages were then analyzed genetically. All three KPP22-resistant PAO1 clones, which were deficient for the O5 antigen, had a common nonsense mutation in thewzygene. All the KPP22 mutant phage genomes showed the same four missense mutations in the open reading framesorf060,orf065, andorf086. The information obtained in this study should be useful for further development of safe and efficient phage therapy.IMPORTANCEPseudomonas aeruginosacauses serious intractable infections in humans and animals; bacteriophage (phage) therapy has been utilized to treatP. aeruginosainfections, and phages that belong to the PB1-like virus genus in the familyMyoviridaehave been used as therapeutic phages. The preadapted phage is trained in advance through the antagonistic evolution of bacteria and phage and is proposed to be used to achieve safer and more effective phage therapy. In this study, to understand the phage preadaptation, thein vitroshort-term antagonistic evolution was studied usingP. aeruginosastrain PAO1 and the newly isolated PB1-like phage KPP22. Phage KPP22 was characterized, and the molecular framework regarding the phage preadaptation of KPP22 was elucidated. The importance of study of antagonistic evolution of bacteria and phage in phage therapy is discussed.

scholarly journals Efficacy of OH-CATH30 and Its Analogs against Drug-Resistant BacteriaIn Vitroand in Mouse Models

2012 ◽  
Vol 56 (6) ◽  
pp. 3309-3317 ◽  
Author(s):  
Sheng-An Li ◽  
Wen-Hui Lee ◽  
Yun Zhang
Keyword(s):  
Mouse Models ◽  
Bacterial Infections ◽  
Resistant Bacteria ◽  
Infection Model ◽  
Drug Resistant ◽  
Content Type ◽  
E Coli ◽  
Drug Resistant Bacteria

ABSTRACTAntimicrobial peptides (AMPs) have been considered alternatives to conventional antibiotics for drug-resistant bacterial infections. However, their comparatively high toxicity toward eukaryotic cells and poor efficacyin vivohamper their clinical application. OH-CATH30, a novel cathelicidin peptide deduced from the king cobra, possesses potent antibacterial activityin vitro. The objective of this study is to evaluate the efficacy of OH-CATH30 and its analog OH-CM6 against drug-resistant bacteriain vitroandin vivo. The MICs of OH-CATH30 and OH-CM6 ranged from 1.56 to 12.5 μg/ml against drug-resistant clinical isolates of several pathogenic species, includingEscherichia coli,Pseudomonas aeruginosa, and methicillin-resistantStaphylococcus aureus. The MICs of OH-CATH30 and OH-CM6 were slightly altered in the presence of 25% human serum. OH-CATH30 and OH-CM6 killedE. coliquickly (within 60 min) by disrupting the bacterial cytoplasmic membrane. Importantly, the 50% lethal doses (LD50) of OH-CATH30 and OH-CM6 in mice following intraperitoneal (i.p.) injection were 120 mg/kg of body weight and 100 mg/kg, respectively, and no death was observed at any dose up to 160 mg/kg following subcutaneous (s.c.) injection. Moreover, 10 mg/kg OH-CATH30 or OH-CM6 significantly decreased the bacterial counts as well as the inflammatory response in a mouse thigh infection model and rescued infected mice in a bacteremia model induced by drug-resistantE. coli. Taken together, our findings demonstrate that the natural cathelicidin peptide OH-CATH30 and its analogs exhibit relatively low toxicity and potent efficacy in mouse models, indicating that they may have therapeutic potential against the systemic infections caused by drug-resistant bacteria.

scholarly journals Antimicrobial and Biophysical Properties of Surfactant Supplemented with an Antimicrobial Peptide for Treatment of Bacterial Pneumonia

2015 ◽  
Vol 59 (6) ◽  
pp. 3075-3083 ◽  
Author(s):  
Brandon J. H. Banaschewski ◽  
Edwin J. A. Veldhuizen ◽  
Eleonora Keating ◽  
Henk P. Haagsman ◽  
Yi Y. Zuo ◽  
...  
Keyword(s):  
Bacterial Pneumonia ◽  
Bacterial Infections ◽  
Multidrug Resistant ◽  
Health Concern ◽  
Exogenous Surfactant ◽  
Resistant Bacteria ◽  
Biophysical Properties ◽  
Surfactant Mixtures ◽  
Content Type

ABSTRACTAntibiotic-resistant bacterial infections represent an emerging health concern in clinical settings, and a lack of novel developments in the pharmaceutical pipeline is creating a “perfect storm” for multidrug-resistant bacterial infections. Antimicrobial peptides (AMPs) have been suggested as future therapeutics for these drug-resistant bacteria, since they have potent broad-spectrum activity, with little development of resistance. Due to the unique structure of the lung, bacterial pneumonia has the additional problem of delivering antimicrobials to the site of infection. One potential solution is coadministration of AMPs with exogenous surfactant, allowing for distribution of the peptides to distal airways and opening of collapsed lung regions. The objective of this study was to test various surfactant-AMP mixtures with regard to maintaining pulmonary surfactant biophysical properties and bactericidal functions. We compared the properties of four AMPs (CATH-1, CATH-2, CRAMP, and LL-37) suspended in bovine lipid-extract surfactant (BLES) by assessing surfactant-AMP mixture biophysical and antimicrobial functions. Antimicrobial activity was tested against methillicin-resistantStaphylococcus aureusandPseudomonas aeruginosa. All AMP/surfactant mixtures exhibited an increase of spreading compared to a BLES control. BLES+CATH-2 mixtures had no significantly different minimum surface tension versus the BLES control. Compared to the other cathelicidins, CATH-2 retained the most bactericidal activity in the presence of BLES. The BLES+CATH-2 mixture appears to be an optimal surfactant-AMP mixture based onin vitroassays. Future directions involve investigating the potential of this mixture in animal models of bacterial pneumonia.

scholarly journals Exploring the Pharmacokinetic/Pharmacodynamic Relationship of Relebactam (MK-7655) in Combination with Imipenem in a Hollow-Fiber Infection Model

2018 ◽  
Vol 62 (5) ◽  
Author(s):  
Jin Wu ◽  
Fred Racine ◽  
Michael K. Wismer ◽  
Katherine Young ◽  
Donna M. Carr ◽  
...  
Keyword(s):  
Hollow Fiber ◽  
Bacterial Infections ◽  
New Drugs ◽  
Dose Fractionation ◽  
Resistant Bacteria ◽  
Infection Model ◽  
Time Curve ◽  
Content Type ◽  
Relationship Of

ABSTRACT Resistance to antibiotics among bacterial pathogens is rapidly spreading, and therapeutic options against multidrug-resistant bacteria are limited. There is an urgent need for new drugs, especially those that can circumvent the broad array of resistance pathways that bacteria have evolved. In this study, we assessed the pharmacokinetic/pharmacodynamic relationship of the novel β-lactamase inhibitor relebactam (REL; MK-7655) in a hollow-fiber infection model. REL is intended for use with the carbapenem β-lactam antibiotic imipenem for the treatment of Gram-negative bacterial infections. In this study, we used an in vitro hollow-fiber infection model to confirm the efficacy of human exposures associated with the phase 2 doses (imipenem at 500 mg plus REL at 125 or 250 mg administered intravenously every 6 h as a 30-min infusion) against imipenem-resistant strains of Pseudomonas aeruginosa and Klebsiella pneumoniae . Dose fractionation experiments confirmed that the pharmacokinetic parameter that best correlated with REL activity is the area under the concentration-time curve, consistent with findings in a murine pharmacokinetic/pharmacodynamic model. Determination of the pharmacokinetic/pharmacodynamic relationship between β-lactam antibiotics and β-lactamase inhibitors is complex, as there is an interdependence between their respective exposure-response relationships. Here, we show that this interdependence could be captured by treating the MIC of imipenem as dynamic: it changes with time, and this change is directly related to REL levels. For the strains tested, the percentage of the dosing interval time that the concentration remains above the dynamic MIC for imipenem was maintained at the carbapenem target of 30 to 40%, required for maximum efficacy, for imipenem at 500 mg plus REL at 250 mg.

scholarly journals Phage Therapy: a Step Forward in the Treatment of Pseudomonas aeruginosa Infections

2015 ◽  
Vol 89 (15) ◽  
pp. 7449-7456 ◽  
Author(s):  
Diana P. Pires ◽  
Diana Vilas Boas ◽  
Sanna Sillankorva ◽  
Joana Azeredo
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Bacterial Infections ◽  
Therapeutic Strategy ◽  
Phage Therapy ◽  
Content Type ◽  
Common Causes ◽  
Health Care Associated Infections ◽  
Common Infection

Antimicrobial resistance constitutes one of the major worldwide public health concerns. Bacteria are becoming resistant to the vast majority of antibiotics, and nowadays, a common infection can be fatal. To address this situation, the use of phages for the treatment of bacterial infections has been extensively studied as an alternative therapeutic strategy. SincePseudomonas aeruginosais one of the most common causes of health care-associated infections, many studies have reported thein vitroandin vivoantibacterial efficacy of phage therapy against this bacterium. This review collects data of all theP. aeruginosaphages sequenced to date, providing a better understanding about their biodiversity. This review further addresses thein vitroandin vivoresults obtained by using phages to treat or preventP. aeruginosainfections as well as the major hurdles associated with this therapy.

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 Bacteriophages to Control Multi-Drug Resistant Enterococcus faecalis Infection of Dental Root Canals

2021 ◽  
Vol 9 (3) ◽  
pp. 517
Author(s):  
Mohamed El-Telbany ◽  
Gamal El-Didamony ◽  
Ahmed Askora ◽  
Eman Ariny ◽  
Dalia Abdallah ◽  
...  
Keyword(s):  
Enterococcus Faecalis ◽  
Root Canal ◽  
Phage Therapy ◽  
Ex Vivo ◽  
Burst Size ◽  
Resistant Bacteria ◽  
Drug Resistant ◽  
Range Analysis ◽  
Root Canals

Phage therapy is an alternative treatment to antibiotics that can overcome multi-drug resistant bacteria. In this study, we aimed to isolate and characterize lytic bacteriophages targeted against Enterococcus faecalis isolated from root canal infections obtained from clinics at the Faculty of Dentistry, Ismalia, Egypt. Bacteriophage, vB_ZEFP, was isolated from concentrated wastewater collected from hospital sewage. Morphological and genomic analysis revealed that the phage belongs to the Podoviridae family with a linear double-stranded DNA genome, consisting of 18,454, with a G + C content of 32.8%. Host range analysis revealed the phage could infect 10 of 13 E. faecalis isolates exhibiting a range of antibiotic resistances recovered from infected root canals with efficiency of plating values above 0.5. One-step growth curves of this phage showed that it has a burst size of 110 PFU per infected cell, with a latent period of 10 min. The lytic activity of this phage against E. faecalis biofilms showed that the phage was able to control the growth of E. faecalis in vitro. Phage vB_ZEFP could also prevent ex-vivo E. faecalis root canal infection. These results suggest that phage vB_ZEFP has potential for application in phage therapy and specifically in the prevention of infection after root canal treatment.

scholarly journals In VitroAntibacterial Activity of NB-003 against Propionibacterium acnes

2011 ◽  
Vol 55 (9) ◽  
pp. 4211-4217 ◽  
Author(s):  
J. Pannu ◽  
A. McCarthy ◽  
A. Martin ◽  
T. Hamouda ◽  
S. Ciotti ◽  
...  
Keyword(s):  
Bacterial Infections ◽  
Propionibacterium Acnes ◽  
Resistant Mutant ◽  
Microtiter Plate ◽  
Content Type ◽  
Oil In Water ◽  
Complete Disruption ◽  
Kinetics Of ◽  
Gel Formulations

ABSTRACTNB-003 and NB-003 gel formulations are oil-in-water nanoemulsions designed for use in bacterial infections.In vitrosusceptibility ofPropionibacterium acnesto NB-003 formulations and comparator drugs was evaluated. Both NB-003 formulations were bactericidal against allP. acnesisolates, including those that were erythromycin, clindamycin, and/or tetracycline resistant. In the absence of sebum, the MIC90s/minimum bactericidal concentrations (MBC90s) for NB-003, NB-003 gel, salicylic acid (SA), and benzoyl peroxide (BPO) were 0.5/2.0, 1.0/2.0, 1,000/2,000, and 50/200 μg/ml, respectively. In the presence of 50% sebum, the MIC90s/MBC90s of NB003 and BPOs increased to 128/1,024 and 400/1,600 μg/ml, respectively. The MIC90s/MBC90s of SA were not significantly impacted by the presence of sebum. A reduction in the MBC90s for NB-003 and BPO was observed when 2% SA or 0.5% BPO was integrated into the formulation, resulting in MIC90s/MBC90s of 128/256 μg/ml for NB003 and 214/428 μg/ml for BPO. The addition of EDTA enhanced thein vitroefficacy of 0.5% NB-003 in the presence or absence of 25% sebum. The addition of 5 mM EDTA to each well of the microtiter plate resulted in a >16- and >256-fold decrease in MIC90and MBC90, yielding a more potent MIC90/MBC90of ≤1/<1 μg/ml. The kinetics of bactericidal activity of NB-003 againstP. acneswere compared to those of a commercially available product of BPO. Electron micrographs ofP. acnestreated with NB-003 showed complete disruption of bacteria. Assessment of spontaneous resistance ofP. acnesrevealed no stably resistant mutant strains.

Sign in / Sign up

Export Citation Format

Share Document