Pathogenicity Genomic Island-Associated CrpP-Like Fluoroquinolone-Modifying Enzymes among Pseudomonas aeruginosa Clinical Isolates in Europe

ABSTRACT Many transferable quinolone resistance mechanisms have been identified in Gram-negative bacteria. The plasmid-encoded 65-amino-acid-long ciprofloxacin-modifying enzyme CrpP was recently identified in Pseudomonas aeruginosa isolates. We analyzed a collection of 100 clonally unrelated and multidrug-resistant P. aeruginosa clinical isolates, among which 46 were positive for crpP-like genes, encoding five CrpP variants conferring variable levels of reduced susceptibility to fluoroquinolones. These crpP-like genes were chromosomally located as part of pathogenicity genomic islands.

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Heterogeneous and Flexible Transmission ofmcr-1in Hospital-AssociatedEscherichia coli

mBio ◽

10.1128/mbio.00943-18 ◽

2018 ◽

Vol 9 (4) ◽

Cited By ~ 23

Author(s):

Yingbo Shen ◽

Zuowei Wu ◽

Yang Wang ◽

Rong Zhang ◽

Hong-Wei Zhou ◽

...

Keyword(s):

Escherichia Coli ◽

Genomic Analysis ◽

Multidrug Resistant ◽

Fluoroquinolone Resistance ◽

Gram Negative Bacteria ◽

Colistin Resistance ◽

Gram Negative ◽

Content Type ◽

E Coli ◽

Genes Encoding

ABSTRACTThe recent emergence of a transferable colistin resistance mechanism, MCR-1, has gained global attention because of its threat to clinical treatment of infections caused by multidrug-resistant Gram-negative bacteria. However, the possible transmission route ofmcr-1amongEnterobacteriaceaespecies in clinical settings is largely unknown. Here, we present a comprehensive genomic analysis ofEscherichia coliisolates collected in a hospital in Hangzhou, China. We found thatmcr-1-carrying isolates from clinical infections and feces of inpatients and healthy volunteers were genetically diverse and were not closely related phylogenetically, suggesting that clonal expansion is not involved in the spread ofmcr-1. Themcr-1gene was found on either chromosomes or plasmids, but in most of theE. coliisolates,mcr-1was carried on plasmids. The genetic context of the plasmids showed considerable diversity as evidenced by the different functional insertion sequence (IS) elements, toxin-antitoxin (TA) systems, heavy metal resistance determinants, and Rep proteins of broad-host-range plasmids. Additionally, the genomic analysis revealed nosocomial transmission ofmcr-1and the coexistence ofmcr-1with other genes encoding β-lactamases and fluoroquinolone resistance in theE. coliisolates. These findings indicate thatmcr-1is heterogeneously disseminated in both commensal and pathogenic strains ofE. coli, suggest the high flexibility of this gene in its association with diverse genetic backgrounds of the hosts, and provide new insights into the genome epidemiology ofmcr-1among hospital-associatedE. colistrains.IMPORTANCEColistin represents one of the very few available drugs for treating infections caused by extensively multidrug-resistant Gram-negative bacteria. The recently emergentmcr-1colistin resistance gene threatens the clinical utility of colistin and has gained global attention. Howmcr-1spreads in hospital settings remains unknown and was investigated by whole-genome sequencing ofmcr-1-carryingEscherichia coliin this study. The findings revealed extraordinary flexibility ofmcr-1in its spread among genetically diverseE. colihosts and plasmids, nosocomial transmission ofmcr-1-carryingE. coli, and the continuous emergence of novel Inc types of plasmids carryingmcr-1and newmcr-1variants. Additionally,mcr-1was found to be frequently associated with other genes encoding β-lactams and fluoroquinolone resistance. These findings provide important information on the transmission and epidemiology ofmcr-1and are of significant public health importance as the information is expected to facilitate the control of this significant antibiotic resistance threat.

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Inactivation of the Pseudomonas -Derived Cephalosporinase-3 (PDC-3) by Relebactam

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.02406-17 ◽

2018 ◽

Vol 62 (5) ◽

Cited By ~ 12

Author(s):

Melissa D. Barnes ◽

Christopher R. Bethel ◽

Jim Alsop ◽

Scott A. Becka ◽

Joseph D. Rutter ◽

...

Keyword(s):

Pseudomonas Aeruginosa ◽

Multidrug Resistant ◽

Clinical Isolates ◽

Gram Negative ◽

Content Type ◽

Life Threatening ◽

Lactamase Inhibitor

ABSTRACT Pseudomonas aeruginosa is a prevalent and life-threatening Gram-negative pathogen. Pseudomonas -derived cephlosporinase (PDC) is the major inducible cephalosporinase in P. aeruginosa . In this investigation, we show that relebactam, a diazabicyclooctane β-lactamase inhibitor, potently inactivates PDC-3, with a k 2 / K of 41,400 M −1 s −1 and a k off of 0.00095 s −1 . Relebactam restored susceptibility to imipenem in 62% of multidrug-resistant P. aeruginosa clinical isolates, while only 21% of isolates were susceptible to imipenem-cilastatin alone. Relebactam promises to increase the efficacy of imipenem-cilastatin against P. aeruginosa .

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Problematic clinical isolates of Pseudomonas aeruginosa from the university hospitals in Sofia, Bulgaria: current status of antimicrobial resistance and prevailing resistance mechanisms

Journal of Medical Microbiology ◽

10.1099/jmm.0.46986-0 ◽

2007 ◽

Vol 56 (7) ◽

pp. 956-963 ◽

Cited By ~ 17

Author(s):

Tanya Strateva ◽

Vessela Ouzounova-Raykova ◽

Boyka Markova ◽

Albena Todorova ◽

Yulia Marteva-Proevska ◽

...

Keyword(s):

Pseudomonas Aeruginosa ◽

Antimicrobial Agents ◽

Carbapenem Resistance ◽

Multidrug Resistant ◽

Resistance Mechanisms ◽

Clinical Isolates ◽

Current Status ◽

University Hospitals ◽

Active Efflux ◽

Genes Encoding

A total of 203 clinical isolates of Pseudomonas aeruginosa was collected during 2001–2006 from five university hospitals in Sofia, Bulgaria, to assess the current levels of antimicrobial susceptibility and to evaluate resistance mechanisms to antipseudomonal antimicrobial agents. The antibiotic resistance rates against the following antimicrobials were: carbenicillin 93.1 %, azlocillin 91.6 %, piperacillin 86.2 %, piperacillin/tazobactam 56.8 %, ceftazidime 45.8 %, cefepime 48.9 %, cefpirome 58.2 %, aztreonam 49.8 %, imipenem 42.3 %, meropenem 45.5 %, amikacin 59.1 %, gentamicin 79.7 %, tobramycin 89.6 %, netilmicin 69.6 % and ciprofloxacin 80.3 %. A total of 101 of the studied P. aeruginosa isolates (49.8 %) were multidrug resistant. Structural genes encoding class A and class D β-lactamases showed the following frequencies: bla VEB-1 33.1 %, bla PSE-1 22.5 %, bla PER-1 0 %, bla OXA-groupI 41.3 % and bla OXA-groupII 8.8 %. IMP- and VIM-type carbapenemases were not detected. In conclusion, the studied clinical strains of P. aeruginosa were problematic nosocomial pathogens. VEB-1 extended-spectrum β-lactamases appear to have a significant presence among clinical P. aeruginosa isolates from Sofia. Carbapenem resistance was related to non-enzymic mechanisms such as a deficiency of OprD proteins and active efflux.

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Pseudomonas aeruginosa Clinical Isolates in Nepal Coproducing Metallo-β-Lactamases and 16S rRNA Methyltransferases

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.00694-17 ◽

2017 ◽

Vol 61 (9) ◽

Cited By ~ 13

Author(s):

Tatsuya Tada ◽

Kayo Shimada ◽

Kazuhito Satou ◽

Takashi Hirano ◽

Bharat M. Pokhrel ◽

...

Keyword(s):

Pseudomonas Aeruginosa ◽

16S Rrna ◽

Multidrug Resistant ◽

Clinical Isolates ◽

Content Type ◽

First Report ◽

Genes Encoding

ABSTRACT A total of 11 multidrug-resistant Pseudomonas aeruginosa clinical isolates were obtained in Nepal. Four of these isolates harbored genes encoding one or more carbapenemases (DIM-1, NDM-1, and/or VIM-2), and five harbored genes encoding a 16S rRNA methyltransferase (RmtB4 or RmtF2). A novel RmtF variant, RmtF2, had a substitution (K65E) compared with the same gene in RmtF. To our knowledge, this is the first report describing carbapenemase- and 16S rRNA methyltransferase-coproducing P. aeruginosa clinical isolates in Nepal.

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Pseudomonas aeruginosa Contact-Dependent Growth Inhibition Plays Dual Role in Host-Pathogen Interactions

mSphere ◽

10.1128/msphere.00336-17 ◽

2017 ◽

Vol 2 (6) ◽

Cited By ~ 19

Author(s):

Jeffrey A. Melvin ◽

Jordan R. Gaston ◽

Shawn N. Phillips ◽

Michael J. Springer ◽

Christopher W. Marshall ◽

...

Keyword(s):

Pseudomonas Aeruginosa ◽

Acute Infection ◽

Multidrug Resistant ◽

Gram Negative Bacteria ◽

Microbial Pathogenesis ◽

Host Pathogen Interactions ◽

Gram Negative ◽

Content Type ◽

Disease Outcomes ◽

Host Pathogen

ABSTRACT How bacteria compete and communicate with each other is an increasingly recognized aspect of microbial pathogenesis with a major impact on disease outcomes. Gram-negative bacteria have recently been shown to employ a contact-dependent toxin-antitoxin system to achieve both competition and regulation of their physiology. Here, we show that this system is vital for virulence in acute infection as well as for establishment of chronic infection in the multidrug-resistant pathogen Pseudomonas aeruginosa. Greater understanding of the mechanisms underlying bacterial virulence and infection is important for the development of effective therapeutics in the era of increasing antimicrobial resistance. Microorganisms exist in a diverse ecosystem and have evolved many different mechanisms for sensing and influencing the polymicrobial environment around them, utilizing both diffusible and contact-dependent signals. Contact-dependent growth inhibition (CDI) is one such communication system employed by Gram-negative bacteria. In addition to CDI mediation of growth inhibition, recent studies have demonstrated CDI-mediated control of communal behaviors such as biofilm formation. We postulated that CDI may therefore play an active role in host-pathogen interactions, allowing invading strains to establish themselves at polymicrobial mucosal interfaces through competitive interactions while simultaneously facilitating pathogenic capabilities via CDI-mediated signaling. Here, we show that Pseudomonas aeruginosa produces two CDI systems capable of mediating competition under conditions of growth on a surface or in liquid. Furthermore, we demonstrated a novel role for these systems in contributing to virulence in acute infection models, likely via posttranscriptional regulation of beneficial behaviors. While we did not observe any role for the P. aeruginosa CDI systems in biofilm biogenesis, we did identify for the first time robust CDI-mediated competition during interaction with a mammalian host using a model of chronic respiratory tract infection, as well as evidence that CDI expression is maintained in chronic lung infections. These findings reveal a previously unappreciated role for CDI in host-pathogen interactions and emphasize their importance during infection. IMPORTANCE How bacteria compete and communicate with each other is an increasingly recognized aspect of microbial pathogenesis with a major impact on disease outcomes. Gram-negative bacteria have recently been shown to employ a contact-dependent toxin-antitoxin system to achieve both competition and regulation of their physiology. Here, we show that this system is vital for virulence in acute infection as well as for establishment of chronic infection in the multidrug-resistant pathogen Pseudomonas aeruginosa. Greater understanding of the mechanisms underlying bacterial virulence and infection is important for the development of effective therapeutics in the era of increasing antimicrobial resistance.

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A Selective Culture Medium for Screening Ceftazidime-Avibactam Resistance in Enterobacterales and Pseudomonas aeruginosa

Journal of Clinical Microbiology ◽

10.1128/jcm.00965-20 ◽

2020 ◽

Vol 58 (9) ◽

Cited By ~ 1

Author(s):

Mustafa Sadek ◽

Laurent Poirel ◽

Camille Tinguely ◽

Patrice Nordmann

Keyword(s):

Pseudomonas Aeruginosa ◽

Lower Limit ◽

Culture Medium ◽

Limit Of Detection ◽

Resistance Mechanisms ◽

Gram Negative Bacteria ◽

Excellent Performance ◽

Gram Negative ◽

Content Type ◽

Selective Culture Medium

ABSTRACT The SuperCAZ/AVI medium was developed for screening ceftazidime-avibactam (CZA) resistance among Gram-negative bacteria (Enterobacterales and Pseudomonas aeruginosa). It was evaluated using 50 CZA-susceptible and 42 CZA-resistant Gram-negative isolates. Its sensitivity and specificity of detection were 100%. Excellent performance of the medium was also observed by testing spiked stools, with the lower limit of detection ranging from 101 to 102 CFU/ml. This screening medium provides the opportunity to detect CZA-resistant isolates regardless of their resistance mechanisms.

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Evaluation of the Revogene Carba C Assay for Detection and Differentiation of Carbapenemase-Producing Gram-Negative Bacteria

Journal of Clinical Microbiology ◽

10.1128/jcm.01927-19 ◽

2020 ◽

Vol 58 (4) ◽

Cited By ~ 2

Author(s):

Delphine Girlich ◽

Marine Laguide ◽

Laurent Dortet ◽

Thierry Naas

Keyword(s):

Pseudomonas Aeruginosa ◽

Nucleic Acid ◽

Sensitivity And Specificity ◽

Multidrug Resistant ◽

Gram Negative Bacteria ◽

Microbiology Laboratory ◽

Bacterial Host ◽

Gram Negative ◽

Content Type

ABSTRACT The Revogene Carba C assay (formerly GenePOC Carba assay) is a multiplex nucleic acid-based in vitro diagnostic test intended for the detection of carbapenemase-producing Enterobacterales (CPE) from cultured colonies. This assay was evaluated directly on colonies of 118 well-characterized Enterobacterales with reduced susceptibility to carbapenems and on 49 multidrug-resistant (MDR) Pseudomonas aeruginosa and 40 MDR Acinetobacter baumannii isolates. The Revogene Carba C assay’s performance was high, as it was able to detect the five major carbapenemases (NDM, VIM, IMP, KPC, and OXA-48). In Enterobacterales, sensitivity and specificity were 100%. When extrapolating the results to the French CPE epidemiology between 2012 and 2018, this assay would have detected 99.28% of the 9,624 CPE isolates sent to the French NRC, missing 69 CPE isolates (2 GES-5, 10 OXA-23, 2 TMB-1, 1 SME-4, 53 IMI, and 1 FRI). The overall sensitivity and specificity for CP P. aeruginosa were 93.7 and 100%, respectively, as two rare IMP variants (IMP-31 and -46) were not detected. Extrapolating these results to the French epidemiology of CP P. aeruginosa in 2017, 93.3% would have been identified, missing only 1 DIM and 10 GES variants. The Revogene Carba C assay accurately identified the targeted carbapenemase genes in A. baumannii, but when extrapolating these results to the French CP A. baumannii epidemiology of 2017, only 12.50% of them could be detected, as OXA-23 is the most prevalent carbapenemase in CP A. baumannii. The Revogene Carba C assay showed excellent sensitivity and specificity for the five most common carbapenemases regardless of the bacterial host. It is well adapted to the CPE and CP P. aeruginosa epidemiology of many countries worldwide, which makes it suitable for use in the routine microbiology laboratory, with a time to result of ca. 85 min for eight isolates simultaneously.

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Susceptibility of Colistin-Resistant, Gram-Negative Bacteria to Antimicrobial Peptides and Ceragenins

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.00292-17 ◽

2017 ◽

Vol 61 (8) ◽

Cited By ~ 22

Author(s):

Marjan M. Hashemi ◽

John Rovig ◽

Scott Weber ◽

Brian Hilton ◽

Mehdi M. Forouzan ◽

...

Keyword(s):

Klebsiella Pneumoniae ◽

Antimicrobial Peptides ◽

Lipid A ◽

Resistance Mechanisms ◽

Clinical Isolates ◽

Cross Resistance ◽

Gram Negative Bacteria ◽

Gram Negative ◽

Content Type

ABSTRACT The susceptibility of colistin-resistant clinical isolates of Klebsiella pneumoniae to ceragenins and antimicrobial peptides (AMPs) suggests that there is little to no cross-resistance between colistin and ceragenins/AMPs and that lipid A modifications are found in bacteria with modest changes in susceptibility to ceragenins and with high levels of resistance to colistin. These results suggest that there are differences in the resistance mechanisms to colistin and ceragenins/AMPs.

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Activity of RX-04 Pyrrolocytosine Protein Synthesis Inhibitors against Multidrug-Resistant Gram-Negative Bacteria

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.00689-18 ◽

2018 ◽

Vol 62 (8) ◽

Cited By ~ 2

Author(s):

Anna Vickers ◽

Shazad Mushtaq ◽

Neil Woodford ◽

Michel Doumith ◽

David M. Livermore

Keyword(s):

Pseudomonas Aeruginosa ◽

Protein Synthesis ◽

Acinetobacter Baumannii ◽

Ribosomal Subunit ◽

Multidrug Resistant ◽

Gram Negative Bacteria ◽

Protein Synthesis Inhibitors ◽

Gram Negative ◽

Content Type ◽

Active Analog

ABSTRACT Pyrrolocytosines RX-04A to -D are designed to bind to the bacterial 50S ribosomal subunit differently from currently used antibiotics. The four analogs had broad anti-Gram-negative activity: RX-04A—the most active analog—inhibited 94.7% of clinical Enterobacteriaceae, Acinetobacter baumannii, and Pseudomonas aeruginosa at 0.5 to 4 μg/ml, with no MICs of >8 μg/ml. MICs for multidrug-resistant (MDR) carbapenemase producers were up to 2-fold higher than those for control strains; values were highest for one Serratia isolate with porin and efflux lesions. mcr-1 did not affect MICs.

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Novel Phage Lysin Capable of Killing the Multidrug-Resistant Gram-Negative Bacterium Acinetobacter baumannii in a Mouse Bacteremia Model

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.04641-14 ◽

2015 ◽

Vol 59 (4) ◽

pp. 1983-1991 ◽

Cited By ~ 100

Author(s):

Rolf Lood ◽

Benjamin Y. Winer ◽

Adam J. Pelzek ◽

Roberto Diez-Martinez ◽

Mya Thandar ◽

...

Keyword(s):

Acinetobacter Baumannii ◽

Genomic Library ◽

Multidrug Resistant ◽

Clinical Isolates ◽

Gram Negative ◽

Content Type ◽

Highly Active ◽

Genes Encoding

ABSTRACTAcinetobacter baumannii, a Gram-negative multidrug-resistant (MDR) bacterium, is now recognized as one of the more common nosocomial pathogens. Because most clinical isolates are found to be multidrug resistant, alternative therapies need to be developed to control this pathogen. We constructed a bacteriophage genomic library based on prophages induced from 13A. baumanniistrains and screened it for genes encoding bacteriolytic activity. Using this approach, we identified 21 distinct lysins with different activities and sequence diversity that were capable of killingA. baumannii. The lysin (PlyF307) displaying the greatest activity was further characterized and was shown to efficiently kill (>5-log-unit decrease) all testedA. baumanniiclinical isolates. Treatment with PlyF307 was able to significantly reduce planktonic and biofilmA. baumanniibothin vitroandin vivo. Finally, PlyF307 rescued mice from lethalA. baumanniibacteremia and as such represents the first highly active therapeutic lysin specific for Gram-negative organisms in an array of native lysins found inAcinetobacterphage.

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