Short Proline-Rich Lipopeptide Potentiates Minocycline and Rifampin against Multidrug- and Extensively Drug-Resistant Pseudomonas aeruginosa

ABSTRACT A series of 16 short proline-rich lipopeptides (SPRLPs) were constructed to mimic longer naturally existing proline-rich antimicrobial peptides. Antibacterial assessment revealed that lipopeptides containing hexadecanoic acid (C16) possess optimal antibacterial activity relative to others with shorter lipid components. SPRLPs were further evaluated for their potential to serve as adjuvants in combination with existing antibiotics to enhance antibacterial activity against drug-resistant Pseudomonas aeruginosa. Out of 16 prepared SPRLPs, C12-PRP was found to significantly potentiate the antibiotics minocycline and rifampin against multidrug- and extensively drug-resistant (MDR/XDR) P. aeruginosa clinical isolates. This nonhemolytic C12-PRP is comprised of the heptapeptide sequence PRPRPRP-NH2 acylated to dodecanoic acid (C12) at the N terminus. The adjuvant potency of C12-PRP was apparent by its ability to reduce the MIC of minocycline and rifampin below their interpretative susceptibility breakpoints against MDR/XDR P. aeruginosa. An attempt to optimize C12-PRP through peptidomimetic modification was performed by replacing all l- to d-amino acids. C12-PRP demonstrated that it was amenable to optimization, since synergism with minocycline and rifampin were retained. Moreover, C12-PRP displayed no cytotoxicity against human liver carcinoma HepG2 and human embryonic kidney HEK-293 cell lines. Thus, the SPRLP C12-PRP is a lead adjuvant candidate that warrants further optimization. The discovery of agents that are able to resuscitate the activity of existing antibiotics against drug-resistant Gram-negative pathogens, especially P. aeruginosa, is of great clinical interest.

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Antimicrobial Activity of Ceftazidime-Avibactam Tested against Multidrug-Resistant Enterobacteriaceae and Pseudomonas aeruginosa Isolates from U.S. Medical Centers, 2013 to 2016

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.01045-17 ◽

2017 ◽

Vol 61 (11) ◽

Cited By ~ 52

Author(s):

Helio S. Sader ◽

Mariana Castanheira ◽

Dee Shortridge ◽

Rodrigo E. Mendes ◽

Robert K. Flamm

Keyword(s):

Pseudomonas Aeruginosa ◽

Multidrug Resistant ◽

Drug Resistant ◽

Large Collection ◽

Content Type ◽

Negative Results ◽

Medical Centers ◽

Extensively Drug Resistant ◽

Genes Encoding

ABSTRACT The in vitro activity of ceftazidime-avibactam and many comparator agents was determined against various resistant subsets of organisms selected among 36,380 Enterobacteriaceae and 7,868 Pseudomonas aeruginosa isolates. The isolates were consecutively collected from 94 U.S. hospitals, and all isolates were tested for susceptibility by reference broth microdilution methods in a central monitoring laboratory (JMI Laboratories). Enterobacteriaceae isolates resistant to carbapenems (CRE) and/or ceftazidime-avibactam (MIC ≥ 16 μg/ml) were evaluated for the presence of genes encoding extended-spectrum β-lactamases and carbapenemases. Ceftazidime-avibactam inhibited >99.9% of all Enterobacteriaceae at the susceptible breakpoint of ≤8 μg/ml and was active against multidrug-resistant (MDR; n = 2,953; MIC50/90, 0.25/1 μg/ml; 99.2% susceptible), extensively drug-resistant (XDR; n = 448; MIC50/90, 0.5/2 μg/ml; 97.8% susceptible), and CRE (n = 513; MIC50/90, 0.5/2 μg/ml; 97.5% susceptible) isolates. Only 82.2% of MDR Enterobacteriaceae (n = 2,953) and 64.2% of ceftriaxone-nonsusceptible Klebsiella pneumoniae (n = 1,063) isolates were meropenem susceptible. Among Enterobacter cloacae (22.2% ceftazidime nonsusceptible), 99.8% of the isolates, including 99.3% of the ceftazidime-nonsusceptible isolates, were ceftazidime-avibactam susceptible. Only 23 of 36,380 Enterobacteriaceae (0.06%) isolates were ceftazidime-avibactam nonsusceptible, including 9 metallo-β-lactamase producers and 2 KPC-producing strains with porin alteration; the remaining 12 strains showed negative results for all β-lactamases tested. Ceftazidime-avibactam showed potent activity against P. aeruginosa (MIC50/90, 2/4 μg/ml; 97.1% susceptible), including MDR (MIC50/90, 4/16 μg/ml; 86.5% susceptible) isolates, and inhibited 71.8% of isolates nonsusceptible to meropenem, piperacillin-tazobactam, and ceftazidime (n = 628). In summary, ceftazidime-avibactam demonstrated potent activity against a large collection (n = 44,248) of contemporary Gram-negative bacilli isolated from U.S. patients, including organisms resistant to most currently available agents, such as CRE and meropenem-nonsusceptible P. aeruginosa.

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Two Novel Bacteriophages Improve Survival in Galleria mellonella Infection and Mouse Acute Pneumonia Models Infected with Extensively Drug-Resistant Pseudomonas aeruginosa

Applied and Environmental Microbiology ◽

10.1128/aem.02900-18 ◽

2019 ◽

Vol 85 (9) ◽

Cited By ~ 7

Author(s):

Jongsoo Jeon ◽

Dongeun Yong

Keyword(s):

Pseudomonas Aeruginosa ◽

In Silico ◽

Galleria Mellonella ◽

Drug Resistant ◽

Content Type ◽

Bacteriolytic Activity ◽

Extensively Drug Resistant ◽

Acute Pneumonia

ABSTRACT Extensively drug-resistant Pseudomonas aeruginosa (XDR-PA) is a life-threatening pathogen that causes serious global problems. Here, we investigated two novel P. aeruginosa bacteriophages (phages), Bϕ-R656 and Bϕ-R1836, in vitro, in silico, and in vivo to evaluate the potential of phage therapy to control XDR-PA clinical strains. Bϕ-R656 and Bϕ-R1836 belong to the Siphoviridae family and exhibited broad host ranges which could lyse 18 (64%) and 14 (50%) of the 28 XDR-PA strains. In addition, the two phages showed strong bacteriolytic activity against XDR-PA host strains from pneumonia patients. The whole genomes of Bϕ-R656 and Bϕ-R1836 have linear double-stranded DNA of 60,919 and 37,714 bp, respectively. The complete sequence of Bϕ-R656 had very low similarity to the previously discovered P. aeruginosa phages in GenBank, but phage Bϕ-R1836 exhibited 98% and 91% nucleotide similarity to Pseudomonas phages YMC12/01/R24 and PA1/KOR/2010, respectively. In the two in vivo infection models, treatment with Bϕ-R656 and Bϕ-R1836 enhanced the survival of Galleria mellonella larvae (50% and 60%, respectively) at 72 h postinfection and pneumonia-model mice (66% and 83%, respectively) at 12 days postinfection compared with untreated controls. Treatment with Bϕ-R656 or Bϕ-R1836 also significantly decreased the bacterial load in the lungs of the mouse pneumonia model (>6 log10 CFU and >4 log10 CFU, respectively) on day 5. IMPORTANCE In this study, two novel P. aeruginosa phages, Bϕ-R656 and Bϕ-R1836, were evaluated in vitro, in silico, and in vivo for therapeutic efficacy and safety as an alternative antibacterial agent to control XDR-PA strains collected from pneumonia patients. Both phages exhibited potent bacteriolytic activity and greatly improved survival in G. mellonella larva infection and a mouse acute pneumonia model. Based on these results, we strongly predict that these two new phages could be used as fast-acting and safe alternative biological weapons against XDR-PA infections.

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Draft Genome Sequence of the Extensively Drug-Resistant Pseudomonas aeruginosa Clinical Isolate TUEPA7472

Microbiology Resource Announcements ◽

10.1128/mra.01055-18 ◽

2018 ◽

Vol 7 (12) ◽

Author(s):

Henrike Miess ◽

Ghazaleh Jahanshah ◽

Heike Brötz-Oesterhelt ◽

Matthias Willmann ◽

Silke Peter ◽

...

Keyword(s):

Pseudomonas Aeruginosa ◽

Genome Sequence ◽

Draft Genome ◽

Resistance Mechanisms ◽

Draft Genome Sequence ◽

Drug Resistant ◽

Gram Negative ◽

Content Type ◽

Extensively Drug Resistant ◽

Insight Into

Pseudomonas aeruginosa TUEPA7472 is extensively drug resistant (XDR) and is a representative Gram-negative rod that is multiresistant toward 4 classes of clinically relevant antibiotics (4MRGN). The 6.8-Mb draft genome sequence of this strain provides insight into these resistance mechanisms and the potential of the strain to produce virulence factors.

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Complete Genome Sequences of Four Extensively Drug-Resistant Pseudomonas aeruginosa Strains, Isolated from Adults with Ventilator-Associated Pneumonia at a Tertiary Referral Hospital in Mexico City

Genome Announcements ◽

10.1128/genomea.00925-17 ◽

2017 ◽

Vol 5 (36) ◽

Author(s):

Luis F. Espinosa-Camacho ◽

Gabriela Delgado ◽

Gloria Soberón-Chávez ◽

Luis D. Alcaraz ◽

Jorge Castañon ◽

...

Keyword(s):

Pseudomonas Aeruginosa ◽

Single Molecule ◽

Genomic Islands ◽

Ventilator Associated Pneumonia ◽

Drug Resistant ◽

Tertiary Referral Hospital ◽

Content Type ◽

Pacbio Rs Ii ◽

Extensively Drug Resistant ◽

Class 1

ABSTRACT Four extensively drug-resistant Pseudomonas aeruginosa strains, isolated from patients with pneumonia, were sequenced using PacBio RS-II single-molecule real-time (SMRT) technology. Genome sequence analysis identified great variability among mobile genetic elements, as well as some previously undescribed genomic islands and new variants of class 1 integrons (In1402, In1403, In1404, and In1408).

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Genomics and Susceptibility Profiles of Extensively Drug-Resistant Pseudomonas aeruginosa Isolates from Spain

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.01589-17 ◽

2017 ◽

Vol 61 (11) ◽

Cited By ~ 40

Author(s):

Ester del Barrio-Tofiño ◽

Carla López-Causapé ◽

Gabriel Cabot ◽

Alba Rivera ◽

Natividad Benito ◽

...

Keyword(s):

Pseudomonas Aeruginosa ◽

Illumina Miseq ◽

Resistance Mechanisms ◽

Drug Resistant ◽

Sequencing Data ◽

Aminoglycoside Resistance ◽

Content Type ◽

Extensively Drug Resistant ◽

Susceptibility Profiles

ABSTRACT This study assessed the molecular epidemiology, resistance mechanisms, and susceptibility profiles of a collection of 150 extensively drug-resistant (XDR) Pseudomonas aeruginosa clinical isolates obtained from a 2015 Spanish multicenter study, with a particular focus on resistome analysis in relation to ceftolozane-tazobactam susceptibility. Broth microdilution MICs revealed that nearly all (>95%) of the isolates were nonsusceptible to piperacillin-tazobactam, ceftazidime, cefepime, aztreonam, imipenem, meropenem, and ciprofloxacin. Most of them were also resistant to tobramycin (77%), whereas nonsusceptibility rates were lower for ceftolozane-tazobactam (31%), amikacin (7%), and colistin (2%). Pulsed-field gel electrophoresis–multilocus sequence typing (PFGE-MLST) analysis revealed that nearly all of the isolates belonged to previously described high-risk clones. Sequence type 175 (ST175) was detected in all 9 participating hospitals and accounted for 68% (n = 101) of the XDR isolates, distantly followed by ST244 (n = 16), ST253 (n = 12), ST235 (n = 8), and ST111 (n = 2), which were detected only in 1 to 2 hospitals. Through phenotypic and molecular methods, the presence of horizontally acquired carbapenemases was detected in 21% of the isolates, mostly VIM (17%) and GES enzymes (4%). At least two representative isolates from each clone and hospital (n = 44) were fully sequenced on an Illumina MiSeq. Classical mutational mechanisms, such as those leading to the overexpression of the β-lactamase AmpC or efflux pumps, OprD inactivation, and/or quinolone resistance-determining regions (QRDR) mutations, were confirmed in most isolates and correlated well with the resistance phenotypes in the absence of horizontally acquired determinants. Ceftolozane-tazobactam resistance was not detected in carbapenemase-negative isolates, in agreement with sequencing data showing the absence of ampC mutations. The unique set of mutations responsible for the XDR phenotype of ST175 clone documented 7 years earlier were found to be conserved, denoting the long-term persistence of this specific XDR lineage in Spanish hospitals. Finally, other potentially relevant mutations were evidenced, including those in penicillin-binding protein 3 (PBP3), which is involved in β-lactam (including ceftolozane-tazobactam) resistance, and FusA1, which is linked to aminoglycoside resistance.

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Optimal Meropenem Concentrations To Treat Multidrug-Resistant Pseudomonas aeruginosa Septic Shock

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.06389-11 ◽

2012 ◽

Vol 56 (4) ◽

pp. 2129-2131 ◽

Cited By ~ 46

Author(s):

Fabio Silvio Taccone ◽

Frédéric Cotton ◽

Sandrine Roisin ◽

Jean-Louis Vincent ◽

Frédérique Jacobs

Keyword(s):

Septic Shock ◽

Pseudomonas Aeruginosa ◽

Therapeutic Option ◽

Multidrug Resistant ◽

Drug Dose ◽

Drug Resistant ◽

Standard Drug ◽

Content Type ◽

Extensively Drug Resistant ◽

Extended Infusion

ABSTRACTA patient with septic shock due to extensively drug resistant (XDR)Pseudomonas aeruginosawas cured by optimizing the meropenem (MEM) regimen to obtain at least 40% of the time between two administrations in which drug levels were four times higher than the MIC of the pathogen. As the standard drug dose did not achieve these optimal concentrations, the MEM regimen was progressively increased up to 12 g/day (3 g every 6 h in a 3-h extended infusion), which eventually resulted in sepsis resolution. High MEM dosage may represent a valuable therapeutic option for infection due to multidrug-resistant (MDR) strains, and drug monitoring would allow rapid regimen adjustment in clinical practice.

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Extensively Drug-Resistant Pseudomonas aeruginosa Isolates ContainingblaVIM-2and Elements of Salmonella Genomic Island 2: a New Genetic Resistance Determinant in Northeast Ohio

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.02372-14 ◽

2014 ◽

Vol 58 (10) ◽

pp. 5929-5935 ◽

Cited By ~ 21

Author(s):

Federico Perez ◽

Andrea M. Hujer ◽

Steven H. Marshall ◽

Amy J. Ray ◽

Philip N. Rather ◽

...

Keyword(s):

Health Care ◽

Pseudomonas Aeruginosa ◽

Health Care System ◽

Genomic Island ◽

The United States ◽

Drug Resistant ◽

Term Care ◽

Content Type ◽

Extensively Drug Resistant ◽

Care System

ABSTRACTCarbapenems are a mainstay of treatment for infections caused byPseudomonas aeruginosa. Carbapenem resistance mediated by metallo-β-lactamases (MBLs) remains uncommon in the United States, despite the worldwide emergence of this group of enzymes. Between March 2012 and May 2013, we detected MBL-producingP. aeruginosain a university-affiliated health care system in northeast Ohio. We examined the clinical characteristics and outcomes of patients, defined the resistance determinants and structure of the genetic element harboring theblaMBLgene through genome sequencing, and typed MBL-producingP. aeruginosaisolates using pulsed-field gel electrophoresis (PFGE), repetitive sequence-based PCR (rep-PCR), and multilocus sequence typing (MLST). Seven patients were affected that were hospitalized at three community hospitals, a long-term-care facility, and a tertiary care center; one of the patients died as a result of infection. Isolates belonged to sequence type 233 (ST233) and were extensively drug resistant (XDR), including resistance to all fluoroquinolones, aminoglycosides, and β-lactams; two isolates were nonsusceptible to colistin. TheblaMBLgene was identified asblaVIM-2contained within a class 1 integron (In559), similar to the cassette array previously detected in isolates from Norway, Russia, Taiwan, and Chicago, IL. Genomic sequencing and assembly revealed that In559 was part of a novel 35-kb region that also included a Tn501-like transposon andSalmonellagenomic island 2 (SGI2)-homologous sequences. This analysis of XDR strains producing VIM-2 from northeast Ohio revealed a novel recombination event betweenSalmonellaandP. aeruginosa, heralding a new antibiotic resistance threat in this region's health care system.

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

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.02055-19 ◽

2020 ◽

Vol 64 (3) ◽

Cited By ~ 4

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.

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Ceftazidime-Avibactam Activity against Multidrug-Resistant Pseudomonas aeruginosa Isolated in U.S. Medical Centers in 2012 and 2013

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.05024-14 ◽

2015 ◽

Vol 59 (6) ◽

pp. 3656-3659 ◽

Cited By ~ 55

Author(s):

Helio S. Sader ◽

Mariana Castanheira ◽

Rodrigo E. Mendes ◽

Robert K. Flamm ◽

David J. Farrell ◽

...

Keyword(s):

Pseudomonas Aeruginosa ◽

Multidrug Resistant ◽

Drug Resistant ◽

Broth Microdilution ◽

Content Type ◽

Microdilution Method ◽

Medical Centers ◽

Extensively Drug Resistant ◽

Broth Microdilution Method

ABSTRACTPseudomonas aeruginosaisolates (n= 3,902) from 75 U.S. medical centers were tested against ceftazidime-avibactam and comparator agents by the reference broth microdilution method. Overall, 96.9% of the strains were susceptible (MIC, ≤8 μg/ml) to ceftazidime-avibactam, while the rates of susceptibility for ceftazidime, meropenem, and piperacillin-tazobactam were 83.8, 81.9, and 78.5%, respectively. Multidrug-resistant and extensively drug-resistant phenotypes were observed in 14.9 and 8.7% of the strains, respectively, and 81.0 and 73.7% of the strains were susceptible to ceftazidime-avibactam, respectively.

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Efficacy of Ceftolozane-Tazobactam in Combination with Colistin against Extensively Drug-Resistant Pseudomonas aeruginosa, Including High-Risk Clones, in an In Vitro Pharmacodynamic Model

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.02542-19 ◽

2020 ◽

Vol 64 (4) ◽

Author(s):

María Montero ◽

Sandra Domene Ochoa ◽

Carla López-Causapé ◽

Brian VanScoy ◽

Sonia Luque ◽

...

Keyword(s):

Pseudomonas Aeruginosa ◽

High Risk ◽

Therapeutic Option ◽

Drug Resistant ◽

Chemostat Model ◽

Content Type ◽

Extensively Drug Resistant ◽

Spanish Study ◽

Time Kill

ABSTRACT Combination therapy is an attractive therapeutic option for extensively drug-resistant (XDR) Pseudomonas aeruginosa infections. Colistin has been the only treatment available for these infections for many years, but its results are suboptimal. Ceftolozane-tazobactam (C/T) is a newly available therapeutic option that has shown good antipseudomonal activity, even against a number of XDR P. aeruginosa strains. However, data about combinations containing C/T are scarce. The aim of this study was to analyze the activity of C/T and colistin alone and in combination against a collection of XDR P. aeruginosa strains containing 24 representative clinical isolates from a multicentre Spanish study. Twenty-four time-kill experiments performed over 24 h were conducted in duplicate to determine the effects of colistin and C/T alone and combined. An in vitro pharmacodynamic chemostat model then was used to validate this combination against three selected XDR P. aeruginosa ST175 isolates with different susceptibility levels to C/T. Static time-kill assays demonstrated superior synergistic or additive effect for C/T plus colistin against 21 of the 24 isolates studied. In the in vitro dynamic pharmacokinetic/pharmacodynamic (PK/PD) model, the C/T regimen of 2/1 g every 8 h with a steady-state concentration of 2 mg/liter colistin effectively suppressed the bacterial growth at 24 h. Additive or synergistic interactions were observed for C/T plus colistin against XDR P. aeruginosa strains and particularly against C/T-resistant strains. C/T plus colistin may be a useful treatment for XDR P. aeruginosa infections, including those caused by high risk-clones resistant to C/T.

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