scholarly journals Resistance Evolution against Phage Combinations Depends on the Timing and Order of Exposure

mBio ◽  
2019 ◽  
Vol 10 (5) ◽  
Author(s):  
Rosanna C. T. Wright ◽  
Ville-Petri Friman ◽  
Margaret C. M. Smith ◽  
Michael A. Brockhurst
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Bacterial Infections ◽  
Phage Therapy ◽  
Multidrug Resistant ◽  
Fitness Costs ◽  
Evolutionary Trajectory ◽  
Promising Alternative ◽  
Content Type ◽  
Resistance Evolution

ABSTRACTPhage therapy is a promising alternative to chemotherapeutic antibiotics for the treatment of bacterial infections. However, despite recent clinical uses of combinations of phages to treat multidrug-resistant infections, a mechanistic understanding of how bacteria evolve resistance against multiple phages is lacking, limiting our ability to deploy phage combinations optimally. Here, we show, usingPseudomonas aeruginosaand pairs of phages targeting shared or distinct surface receptors, that the timing and order of phage exposure determine the strength, cost, and mutational basis of resistance. Whereas sequential exposure allowed bacteria to acquire multiple resistance mutations effective against both phages, this evolutionary trajectory was prevented by simultaneous exposure, resulting in quantitatively weaker resistance. The order of phage exposure determined the fitness costs of sequential resistance, such that certain sequential orders imposed much higher fitness costs than the same phage pair in the reverse order. Together, these data suggest that phage combinations can be optimized to limit the strength of evolved resistances while maximizing their associated fitness costs to promote the long-term efficacy of phage therapy.IMPORTANCEGlobally rising rates of antibiotic resistance have renewed interest in phage therapy where combinations of phages have been successfully used to treat multidrug-resistant infections. To optimize phage therapy, we first need to understand how bacteria evolve resistance against combinations of multiple phages. Here, we use simple laboratory experiments and genome sequencing to show that the timing and order of phage exposure determine the strength, cost, and mutational basis of resistance evolution in the opportunistic pathogenPseudomonas aeruginosa. These findings suggest that phage combinations can be optimized to limit the emergence and persistence of resistance, thereby promoting the long-term usefulness of phage therapy.

scholarly journals The Concerted Action of Two B3-Like Prophage Genes Excludes Superinfecting Bacteriophages by Blocking DNA Entry into Pseudomonas aeruginosa

2020 ◽  
Vol 94 (15) ◽  
Author(s):  
Marco Antonio Carballo-Ontiveros ◽  
Adrián Cazares ◽  
Pablo Vinuesa ◽  
Luis Kameyama ◽  
Gabriel Guarneros
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Pathogenic Bacteria ◽  
Phage Therapy ◽  
Alternative Therapy ◽  
Multidrug Resistant ◽  
Open Reading Frames ◽  
Resistant Bacteria ◽  
Content Type ◽  
Secondary Infections ◽  
Genes Encoding

ABSTRACT In this study, we describe seven vegetative phage genomes homologous to the historic phage B3 that infect Pseudomonas aeruginosa. Like other phage groups, the B3-like group contains conserved (core) and variable (accessory) open reading frames (ORFs) grouped at fixed regions in their genomes; however, in either case, many ORFs remain without assigned functions. We constructed lysogens of the seven B3-like phages in strain Ps33 of P. aeruginosa, a novel clinical isolate, and assayed the exclusion phenotype against a variety of temperate and virulent superinfecting phages. In addition to the classic exclusion conferred by the phage immunity repressor, the phenotype observed in B3-like lysogens suggested the presence of other exclusion genes. We set out to identify the genes responsible for this exclusion phenotype. Phage Ps56 was chosen as the study subject since it excluded numerous temperate and virulent phages. Restriction of the Ps56 genome, cloning of several fragments, and resection of the fragments that retained the exclusion phenotype allowed us to identify two core ORFs, so far without any assigned function, as responsible for a type of exclusion. Neither gene expressed separately from plasmids showed activity, but the concurrent expression of both ORFs is needed for exclusion. Our data suggest that phage adsorption occurs but that phage genome translocation to the host’s cytoplasm is defective. To our knowledge, this is the first report on this type of exclusion mediated by a prophage in P. aeruginosa. IMPORTANCE Pseudomonas aeruginosa is a Gram-negative bacterium frequently isolated from infected immunocompromised patients, and the strains are resistant to a broad spectrum of antibiotics. Recently, the use of phages has been proposed as an alternative therapy against multidrug-resistant bacteria. However, this approach may present various hurdles. This work addresses the problem that pathogenic bacteria may be lysogenized by phages carrying genes encoding resistance against secondary infections, such as those used in phage therapy. Discovering phage genes that exclude superinfecting phages not only assigns novel functions to orphan genes in databases but also provides insight into selection of the proper phages for use in phage therapy.

scholarly journals Pseudomonas aeruginosa Resistance to Bacteriophages and Its Prevention by Strategic Therapeutic Cocktail Formulation

Antibiotics ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 145
Author(s):  
Andrew Vaitekenas ◽  
Anna S. Tai ◽  
Joshua P. Ramsay ◽  
Stephen M. Stick ◽  
Anthony Kicic
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Bacterial Infections ◽  
Phage Therapy ◽  
Treatment Options ◽  
Rapid Evolution ◽  
Resistance Mechanisms ◽  
Phage Resistance ◽  
Strategic Development ◽  
Promising Alternative ◽  
Narrow Host Range

Antimicrobial resistance poses a significant threat to modern healthcare as it limits treatment options for bacterial infections, particularly impacting those with chronic conditions such as cystic fibrosis (CF). Viscous mucus accumulation in the lungs of individuals genetically predisposed to CF leads to recurrent bacterial infections, necessitating prolonged antimicrobial chemotherapy. Pseudomonas aeruginosa infections are the predominant driver of CF lung disease, and airway isolates are frequently resistant to multiple antimicrobials. Bacteriophages, or phages, are viruses that specifically infect bacteria and are a promising alternative to antimicrobials for CF P. aeruginosa infections. However, the narrow host range of P. aeruginosa-targeting phages and the rapid evolution of phage resistance could limit the clinical efficacy of phage therapy. A promising approach to overcome these issues is the strategic development of mixtures of phages (cocktails). The aim is to combine phages with broad host ranges and target multiple distinct bacterial receptors to prevent the evolution of phage resistance. However, further research is required to identify and characterize phage resistance mechanisms in CF-derived P. aeruginosa, which differ from their non-CF counterparts. In this review, we consider the mechanisms of P. aeruginosa phage resistance and how these could be overcome by an effective future phage therapy formulation.

scholarly journals Ceftolozane-Tazobactam Activity against Pseudomonas aeruginosa Clinical Isolates from U.S. Hospitals: Report from the PACTS Antimicrobial Surveillance Program, 2012 to 2015

2017 ◽  
Vol 61 (7) ◽  
Author(s):  
Dee Shortridge ◽  
Mariana Castanheira ◽  
Michael A. Pfaller ◽  
Robert K. Flamm
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Bacterial Infections ◽  
Multidrug Resistant ◽  
Surveillance Program ◽  
Drug Resistant ◽  
Content Type ◽  
Microdilution Method ◽  
Antimicrobial Surveillance ◽  
Broth Microdilution Method

ABSTRACT The activity of ceftolozane-tazobactam was compared to the activities of 7 antimicrobials against 3,851 Pseudomonas aeruginosa isolates collected from 32 U.S. hospitals in the Program to Assess Ceftolozane-Tazobactam Susceptibility from 2012 to 2015. Ceftolozane-tazobactam and comparator susceptibilities were determined using the CLSI broth microdilution method at a central monitoring laboratory. For ceftolozane-tazobactam, 97.0% of the isolates were susceptible. Susceptibilities of the other antibacterials tested were: amikacin, 96.9%; cefepime, 85.9%; ceftazidime, 85.1%; colistin, 99.2%; levofloxacin, 76.6%; meropenem, 81.8%; and piperacillin-tazobactam, 80.4%. Of the 699 (18.1%) meropenem-nonsusceptible P. aeruginosa isolates, 87.6% were susceptible to ceftolozane-tazobactam. Six hundred seven isolates (15.8%) were classified as multidrug resistant (MDR), and 363 (9.4%) were classified as extensively drug resistant (XDR). Only 1 isolate was considered pandrug resistant, which was resistant to all tested agents, including colistin. Of the 607 MDR isolates, 84.9% were ceftolozane-tazobactam susceptible, and 76.9% of XDR isolates were ceftolozane-tazobactam susceptible. In vitro activity against drug-resistant P. aeruginosa indicates ceftolozane-tazobactam may be an important agent in treating serious bacterial infections.

scholarly journals Bacteriophage Treatment Rescues Mice Infected with Multidrug-Resistant Klebsiella pneumoniae ST258

mBio ◽  
2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Shayla Hesse ◽  
Natalia Malachowa ◽  
Adeline R. Porter ◽  
Brett Freedman ◽  
Scott D. Kobayashi ◽  
...  
Keyword(s):  
Klebsiella Pneumoniae ◽  
Alternative Treatment ◽  
Bacterial Infections ◽  
Phage Therapy ◽  
Treatment Approach ◽  
Multidrug Resistant ◽  
Sequence Type ◽  
Infection Model ◽  
Content Type ◽  
Treatment Groups

ABSTRACT Severe infections caused by multidrug-resistant Klebsiella pneumoniae sequence type 258 (ST258) highlight the need for new therapeutics with activity against this pathogen. Bacteriophage (phage) therapy is an alternative treatment approach for multidrug-resistant bacterial infections that has shown efficacy in experimental animal models and promise in clinical case reports. In this study, we assessed microbiologic, histopathologic, and survival outcomes following systemic administration of phage in ST258-infected mice. We found that prompt treatment with two phages, either individually or in combination, rescued mice with K. pneumoniae ST258 bacteremia. Among the three treatment groups, mice that received combination phage therapy demonstrated the greatest increase in survival and the lowest frequency of phage resistance among bacteria recovered from mouse blood and tissue. Our findings support the utility of phage therapy as an approach for refractory ST258 infections and underscore the potential of this treatment modality to be enhanced through strategic phage selection. IMPORTANCE Infections caused by multidrug-resistant K. pneumoniae pose a serious threat to at-risk patients and present a therapeutic challenge for clinicians. Bacteriophage (phage) therapy is an alternative treatment approach that has been associated with positive clinical outcomes when administered experimentally to patients with refractory bacterial infections. Inasmuch as these experimental treatments are prepared for individual patients and authorized for compassionate use only, they lack the rigor of a clinical trial and therefore cannot provide proof of efficacy. Here, we demonstrate that administration of viable phage provides effective treatment for multidrug-resistant K. pneumoniae (sequence type 258 [ST258]) bacteremia in a murine infection model. Moreover, we compare outcomes among three distinct phage treatment groups and identify potential correlates of therapeutic phage efficacy. These findings constitute an important first step toward optimizing and assessing phage therapy’s potential for the treatment of severe ST258 infection in humans.

scholarly journals A Dimer, but Not Monomer, of Tobramycin Potentiates Ceftolozane against Multidrug-Resistant and Extensively Drug-Resistant Pseudomonas aeruginosa and Delays Resistance Development

2020 ◽  
Vol 64 (3) ◽  
Author(s):  
Temilolu Idowu ◽  
George G. Zhanel ◽  
Frank Schweizer
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Bacterial Infections ◽  
Multidrug Resistant ◽  
Drug Resistant ◽  
Content Type ◽  
Extensively Drug Resistant ◽  
In The Wild ◽  
Tract Infections ◽  
Hospital Acquired

ABSTRACT Ceftolozane-tazobactam is a potent β-lactam/β-lactamase inhibitor combination approved for the treatment of complicated intraabdominal and complicated urinary tract infections and, more recently, the treatment of hospital-acquired and ventilator-associated bacterial pneumonia. Although the activities of ceftolozane are not enhanced by tazobactam against Pseudomonas aeruginosa, it remains the most potent antipseudomonal agent approved to date. Emerging data worldwide has included reports of microbiological failure in patients with serious bacterial infections caused by multidrug-resistant (MDR) P. aeruginosa as a result of ceftolozane resistance developed within therapy. The objective of this study is to compare the efficacy of a tobramycin homodimer plus ceftolozane versus ceftolozane-tazobactam alone against MDR and extensively drug-resistant (XDR) P. aeruginosa. Tobramycin homodimer, a synthetic dimer of two monomeric units of tobramycin, was developed to abrogate the ribosomal properties of tobramycin with a view to mitigating aminoglycoside-related toxicity and resistance. Herein, we report that tobramycin homodimer, a nonribosomal aminoglycoside derivative, potentiates the activities of ceftolozane versus MDR/XDR P. aeruginosa in vitro and delays the emergence of resistance to ceftolozane-tazobactam in the wild-type PAO1 strain. This combination is also more potent than a standard ceftazidime-avibactam combination against these isolates. Conversely, a tobramycin monomer with intrinsic ribosomal properties does not potentiate ceftolozane under similar conditions. Susceptibility and checkerboard studies were assessed using serial 2-fold dilution assays, following the Clinical and Laboratory Standards Institute (CLSI) guidelines. This strategy provides an avenue to further preserve the clinical utility of ceftolozane and enhances its spectrum of activity against one of the most difficult-to-treat pathogens in hospitals.

scholarly journals Evaluation of Gallium Citrate Formulations against a Multidrug-Resistant Strain of Klebsiella pneumoniae in a Murine Wound Model of Infection

2015 ◽  
Vol 59 (10) ◽  
pp. 6484-6493 ◽  
Author(s):  
Mitchell G. Thompson ◽  
Vu Truong-Le ◽  
Yonas A. Alamneh ◽  
Chad C. Black ◽  
Jeff Anderl ◽  
...  
Keyword(s):  
Klebsiella Pneumoniae ◽  
Bacterial Infections ◽  
Multidrug Resistant ◽  
Health Care Facilities ◽  
Topical Formulation ◽  
Promising Alternative ◽  
Content Type ◽  
Wound Model ◽  
Alternative Treatment Strategy

ABSTRACTSkin and soft tissue infections (SSTIs) are a common occurrence in health care facilities with a heightened risk for immunocompromised patients.Klebsiella pneumoniaehas been increasingly implicated as the bacterial agent responsible for SSTIs, and treatment can be challenging as more strains become multidrug resistant (MDR). Therefore, new treatments are needed to counter this bacterial pathogen. Gallium complexes exhibit antimicrobial activity and are currently being evaluated as potential treatment for bacterial infections. In this study, we tested a topical formulation containing gallium citrate (GaCi) for the treatment of wounds infected withK. pneumoniae. First, the MIC againstK. pneumoniaeranged from 0.125 to 2.0 μg/ml GaCi. After thisin vitroefficacy was established, two topical formulations with GaCi (0.1% [wt/vol] and 0.3% [wt/vol]) were tested in a murine wound model of MDRK. pneumoniaeinfection. Gross pathology and histopathology revealedK. pneumoniae-infected wounds appeared to close faster with GaCi treatment and were accompanied by reduced inflammation compared to those of untreated controls. Similarly, quantitative indications of infection remediation, such as reduced weight loss and wound area, suggested that treatment improved outcomes compared to those of untreated controls. Bacterial burdens were measured 1 and 3 days following inoculation, and a 0.5 to 1.5 log reduction of CFU was observed. Lastly, upon scanning electron microscopy analysis, GaCi treatment appeared to prevent biofilm formation on dressings compared to those of untreated controls. These results suggest that with more preclinical testing, a topical application of GaCi may be a promising alternative treatment strategy forK. pneumoniaeSSTI.

scholarly journals Genetic and Chemical Engineering of Phages for Controlling Multidrug-Resistant Bacteria

Antibiotics ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 202
Author(s):  
Dingming Guo ◽  
Jingchao Chen ◽  
Xueyang Zhao ◽  
Yanan Luo ◽  
Menglu Jin ◽  
...  
Keyword(s):  
Bacterial Infections ◽  
Chemical Engineering ◽  
Phage Therapy ◽  
Public Health Problem ◽  
Multidrug Resistant ◽  
Host Recognition ◽  
Resistant Bacteria ◽  
Multidrug Resistant Bacteria ◽  
Promising Alternative ◽  
Review Reports

Along with the excessive use of antibiotics, the emergence and spread of multidrug-resistant bacteria has become a public health problem and a great challenge vis-à-vis the control and treatment of bacterial infections. As the natural predators of bacteria, phages have reattracted researchers’ attentions. Phage therapy is regarded as one of the most promising alternative strategies to fight pathogens in the post-antibiotic era. Recently, genetic and chemical engineering methods have been applied in phage modification. Among them, genetic engineering includes the expression of toxin proteins, modification of host recognition receptors, and interference of bacterial phage-resistant pathways. Chemical engineering, meanwhile, involves crosslinking phage coats with antibiotics, antimicrobial peptides, heavy metal ions, and photothermic matters. Those advances greatly expand the host range of phages and increase their bactericidal efficiency, which sheds light on the application of phage therapy in the control of multidrug-resistant pathogens. This review reports on engineered phages through genetic and chemical approaches. Further, we present the obstacles that this novel antimicrobial has incurred.

scholarly journals Food as a Source for Quorum Sensing Inhibitors: Iberin from Horseradish Revealed as a Quorum Sensing Inhibitor of Pseudomonas aeruginosa

2012 ◽  
Vol 78 (7) ◽  
pp. 2410-2421 ◽  
Author(s):  
Tim Holm Jakobsen ◽  
Steinn Kristinn Bragason ◽  
Richard Kerry Phipps ◽  
Louise Dahl Christensen ◽  
Maria van Gennip ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Quorum Sensing ◽  
Bacterial Infections ◽  
Opportunistic Pathogen ◽  
Multidrug Resistant ◽  
Resistant Bacteria ◽  
Array Detector ◽  
Content Type ◽  
Health Promoting ◽  
Microarray Studies

ABSTRACTFoods with health-promoting effects beyond nutritional values have been gaining increasing research focus in recent years, although not much has been published on this subject in relation to bacterial infections. With respect to treatment, a novel antimicrobial strategy, which is expected to transcend problems with selective pressures for antibiotic resistance, is to interrupt bacterial communication, also known as quorum sensing (QS), by means of signal antagonists, the so-called QS inhibitors (QSIs). Furthermore, QSI agents offer a potential solution to the deficiencies associated with use of traditional antibiotics to treat infections caused by bacterial biofilms and multidrug-resistant bacteria. Several QSIs of natural origin have been identified, and in this study, several common food products and plants were extracted and screened for QSI activity in an attempt to isolate and characterize previously unknown QSI compounds active against the common opportunistic pathogenPseudomonas aeruginosa. Several extracts displayed activity, but horseradish exhibited the highest activity. Chromatographic separation led to the isolation of a potent QSI compound that was identified by liquid chromatography-diode array detector-mass spectrometry (LC-DAD-MS) and nuclear magnetic resonance (NMR) spectroscopy as iberin—an isothiocyanate produced by many members of theBrassicaceaefamily. Real-time PCR (RT-PCR) and DNA microarray studies showed that iberin specifically blocks expression of QS-regulated genes inP. aeruginosa.

scholarly journals Rapid and Consistent Evolution of Colistin Resistance in Extensively Drug-Resistant Pseudomonas aeruginosa during Morbidostat Culture

2017 ◽  
Vol 61 (9) ◽  
Author(s):  
Bianca Dößelmann ◽  
Matthias Willmann ◽  
Matthias Steglich ◽  
Boyke Bunk ◽  
Ulrich Nübel ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Multidrug Resistant ◽  
Colistin Resistance ◽  
Content Type ◽  
Resistance Evolution ◽  
Extensively Drug Resistant ◽  
Evolution Of Resistance ◽  
Resistant Strains ◽  
Detailed Picture

ABSTRACT Colistin is a last-resort antibiotic commonly used against multidrug-resistant strains of Pseudomonas aeruginosa. To investigate the potential for in situ evolution of resistance against colistin and to map the molecular targets of colistin resistance, we exposed two P. aeruginosa isolates to colistin using a continuous-culture device known as a morbidostat. As a result, colistin resistance reproducibly increased 10-fold within 10 days and 100-fold within 20 days, along with highly stereotypic yet strain-specific mutation patterns. The majority of mutations hit the pmrAB two-component signaling system and genes involved in lipopolysaccharide (LPS) synthesis, including lpxC, pmrE, and migA. We tracked the frequencies of all arising mutations by whole-genome deep sequencing every 3 to 4 days to obtain a detailed picture of the dynamics of resistance evolution, including competition and displacement among multiple resistant subpopulations. In 7 out of 18 cultures, we observed mutations in mutS along with a mutator phenotype that seemed to facilitate resistance evolution.

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.

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