scholarly journals FIM-1, a New Acquired Metallo-β-Lactamase from a Pseudomonas aeruginosa Clinical Isolate from Italy

2012 ◽  
Vol 57 (1) ◽  
pp. 410-416 ◽  
Author(s):  
Simona Pollini ◽  
Simona Maradei ◽  
Patrizia Pecile ◽  
Giuseppe Olivo ◽  
Francesco Luzzaro ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Clinical Isolate ◽  
Graft Infection ◽  
Clinical Importance ◽  
Multidrug Resistant ◽  
Amino Acid Identity ◽  
Vascular Graft Infection ◽  
Methoxy Derivative ◽  
Content Type ◽  
E Coli

ABSTRACTAcquired metallo-β-lactamases (MBLs) are resistance determinants of increasing clinical importance in Gram-negative bacterial pathogens, which confer a broad-spectrum β-lactam resistance, including carbapenems. Several such enzymes have been described since the 1990s. In the present study, a novel acquired MBL, named FIM-1, was identified and characterized. TheblaFIM-1gene was cloned from a multidrug-resistantPseudomonas aeruginosaclinical isolate (FI-14/157) cultured from a patient with a vascular graft infection in Florence, Italy. The isolate belonged in the sequence type 235 epidemic clonal lineage. The FIM-1 enzyme is a member of subclass B1 and, among acquired MBLs, exhibited the highest similarity (ca. 40% amino acid identity) with NDM-type enzymes. InP. aeruginosaFI-14/157, theblaFIM-1gene was apparently inserted into the chromosome and associated with ISCR19-like elements that were likely involved in the capture and mobilization of this MBL gene. Transfer experiments of theblaFIM-1gene to anEscherichia colistrain or anotherP. aeruginosastrain by conjugation or electrotransformation were not successful. The FIM-1 protein was produced inE. coliand purified by two chromatography steps. Analysis of the kinetic parameters, carried out with the purified enzyme, revealed that FIM-1 has a broad substrate specificity, with a preference for penicillins (except the 6α-methoxy derivative temocillin) and carbapenems. Aztreonam was not hydrolyzed. Detection of this novel type of acquired MBL in aP. aeruginosaclinical isolate underscores the increasing diversity of such enzymes that can be encountered in the clinical setting.

scholarly journals Draft Genome Sequence of Pseudomonas aeruginosa Strain BWH047, a Sequence Type 235 Multidrug-Resistant Clinical Isolate Expressing High Levels of Colistin Resistance

2019 ◽  
Vol 8 (29) ◽  
Author(s):  
Kelly E. R. Bachta ◽  
Egon A. Ozer ◽  
Alisha Pandit ◽  
Francisco M. Marty ◽  
John J. Mekalanos ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Clinical Isolate ◽  
Genome Sequence ◽  
Draft Genome ◽  
Multidrug Resistant ◽  
Sequence Type ◽  
Draft Genome Sequence ◽  
Colistin Resistance ◽  
Content Type ◽  
Global Epidemic

The Gram-negative bacterium Pseudomonas aeruginosa is often multidrug resistant, associated with global epidemic outbreaks, and responsible for significant morbidity and mortality in hospitalized patients. Here, we present the draft genome sequence of BWH047, a multidrug-resistant P. aeruginosa clinical isolate belonging to the epidemic sequence type 235 and demonstrating high levels of colistin resistance.

scholarly journals Multidrug-Resistant Sequence Type 235 Pseudomonas aeruginosa Clinical Isolates Producing IMP-26 with Increased Carbapenem-Hydrolyzing Activities in Vietnam

2016 ◽  
Vol 60 (11) ◽  
pp. 6853-6858 ◽  
Author(s):  
Tatsuya Tada ◽  
Pham Hong Nhung ◽  
Tohru Miyoshi-Akiyama ◽  
Kayo Shimada ◽  
Mitsuhiro Tsuchiya ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Multidrug Resistant ◽  
Sequence Type ◽  
Clinical Isolates ◽  
Medical Setting ◽  
Single Nucleotide ◽  
Content Type ◽  
E Coli ◽  
Whole Genomes ◽  
Encoding Genes

ABSTRACTForty clinical isolates of multidrug-resistantPseudomonas aeruginosawere obtained in a medical setting in Hanoi, Vietnam. Whole genomes of all 40 isolates were sequenced by MiSeq (Illumina), and phylogenic trees were constructed from the single nucleotide polymorphism concatemers. Of these 40 isolates, 24 (60.0%) harbored metallo-β-lactamase-encoding genes, includingblaIMP-15,blaIMP-26,blaIMP-51, and/orblaNDM-1. Of these 24 isolates, 12 harboredblaIMP-26and belonged to sequence type 235 (ST235).Escherichia coliexpressingblaIMP-26was significantly more resistant to doripenem and meropenem thanE. coliexpressingblaIMP-1andblaIMP-15. IMP-26 showed higher catalytic activity against doripenem and meropenem than IMP-1 and against all carbapenems tested, including doripenem, imipenem, meropenem, and panipenem, than did IMP-15. These data suggest that clinical isolates of multidrug-resistant ST235P. aeruginosaproducing IMP-26 with increased carbapenem-hydrolyzing activities are spreading in medical settings in Vietnam.

scholarly journals IMP-43 and IMP-44 Metallo-β-Lactamases with Increased Carbapenemase Activities in Multidrug-Resistant Pseudomonas aeruginosa

2013 ◽  
Vol 57 (9) ◽  
pp. 4427-4432 ◽  
Author(s):  
Tatsuya Tada ◽  
Tohru Miyoshi-Akiyama ◽  
Kayo Shimada ◽  
Masahiro Shimojima ◽  
Teruo Kirikae
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Amino Acid ◽  
Amino Acid Residue ◽  
Active Site ◽  
Multidrug Resistant ◽  
Amino Acid Sequences ◽  
Medical Settings ◽  
Content Type ◽  
E Coli ◽  
Catalytic Activities

ABSTRACTTwo novel IMP-type metallo-β-lactamase variants, IMP-43 and IMP-44, were identified in multidrug-resistantPseudomonas aeruginosaisolates obtained in medical settings in Japan. Analysis of their predicted amino acid sequences revealed that IMP-43 had an amino acid substitution (Val67Phe) compared with IMP-7 and that IMP-44 had two substitutions (Val67Phe and Phe87Ser) compared with IMP-11. The amino acid residue at position 67 is located at the end of a loop close to the active site, consisting of residues 60 to 66 in IMP-1, and the amino acid residue at position 87 forms a hydrophobic patch close to the active site with other amino acids. AnEscherichia colistrain expressingblaIMP-43was more resistant to doripenem and meropenem but not to imipenem than one expressingblaIMP-7. AnE. colistrain expressingblaIMP-44was more resistant to doripenem, imipenem and meropenem than one expressingblaIMP-11. IMP-43 had more efficient catalytic activities against all three carbapenems than IMP-7, indicating that the Val67Phe substitution contributed to increased catalytic activities against carbapenems. IMP-44 had more efficient catalytic activities against all carbapenems tested than IMP-11, as well as increased activities compared with IMP-43, indicating that both the Val67Phe and Phe87Ser substitutions contributed to increased catalytic activities against carbapenems.

scholarly journals Performance of Four Fosfomycin Susceptibility Testing Methods against an International Collection of Clinical Pseudomonas aeruginosa Isolates

2020 ◽  
Vol 58 (10) ◽  
Author(s):  
Elizabeth C. Smith ◽  
Hunter V. Brigman ◽  
Jadyn C. Anderson ◽  
Christopher L. Emery ◽  
Tiffany E. Bias ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Susceptibility Testing ◽  
Wide Spectrum ◽  
Multidrug Resistant ◽  
Supporting Evidence ◽  
Broth Microdilution ◽  
Testing Methods ◽  
Content Type ◽  
E Coli ◽  
Agar Dilution

ABSTRACT Fosfomycin has been shown to have a wide spectrum of activity against multidrug-resistant Gram-negative bacteria; however, breakpoints have been established only for Escherichia coli or Enterobacterales per the Clinical and Laboratory Standards Institute (CLSI) and the European Committee on Antimicrobial Susceptibility Testing (EUCAST), respectively. A lack of additional organism breakpoints limits clinical use of this agent and has prompted extrapolation of these interpretive categories to other organisms like Pseudomonas aeruginosa without supporting evidence. Further complicating the utility of fosfomycin is the specified method for MIC determination, namely, agar dilution, which is not widely available and is both labor and time intensive. We therefore sought to determine the susceptibility of a large international collection of P. aeruginosa isolates (n = 198) to fosfomycin and to compare testing agreement rates across four methods: agar dilution, broth microdilution, disk diffusion, and Etest. Results were interpreted according to CLSI E. coli breakpoints, with 49.0 to 85.8% considered susceptible, dependent upon the testing method used. Epidemiological cutoff values were calculated and determined to be 256 μg/ml and 512 μg/ml for agar dilution and broth microdilution, respectively. Agreement rates were analyzed using both agar dilution and broth microdilution with a resulting high essential agreement rate of 91.3% between the two susceptibility testing methods. These results indicate that broth microdilution may be a reliable method for fosfomycin susceptibility testing against P. aeruginosa and stress the need for P. aeruginosa-specific breakpoints.

scholarly journals IMP-51, a Novel IMP-Type Metallo-β-Lactamase with Increased Doripenem- and Meropenem-Hydrolyzing Activities, in a Carbapenem-Resistant Pseudomonas aeruginosa Clinical Isolate

2015 ◽  
Vol 59 (11) ◽  
pp. 7090-7093 ◽  
Author(s):  
Tatsuya Tada ◽  
Pham Hong Nhung ◽  
Tohru Miyoshi-Akiyama ◽  
Kayo Shimada ◽  
Doan Mai Phuong ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Pseudomonas Aeruginosa ◽  
Amino Acid ◽  
Clinical Isolate ◽  
Amino Acid Residue ◽  
Active Site ◽  
Medical Setting ◽  
Content Type ◽  
E Coli ◽  
Carbapenem Resistant

ABSTRACTA meropenem-resistantPseudomonas aeruginosaisolate was obtained from a patient in a medical setting in Hanoi, Vietnam. The isolate was found to have a novel IMP-type metallo-β-lactamase, IMP-51, which differed from IMP-7 by an amino acid substitution (Ser262Gly).Escherichia coliexpressingblaIMP-51showed greater resistance to cefoxitin, meropenem, and moxalactam thanE. coliexpressingblaIMP-7. The amino acid residue at position 262 was located near the active site, proximal to the H263 Zn(II) ligand.

scholarly journals Activity of Ceftazidime-Avibactam against Fluoroquinolone-Resistant Enterobacteriaceae and Pseudomonas aeruginosa

2015 ◽  
Vol 59 (6) ◽  
pp. 3059-3065 ◽  
Author(s):  
C. Pitart ◽  
F. Marco ◽  
T. A. Keating ◽  
W. W. Nichols ◽  
J. Vila
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Resistant Mutant ◽  
Fluoroquinolone Resistance ◽  
Cross Resistance ◽  
Content Type ◽  
E Coli ◽  
Microdilution Method ◽  
Broth Microdilution Method ◽  
The Impact

ABSTRACTCeftazidime-avibactam and comparator antibiotics were tested by the broth microdilution method against 200Enterobacteriaceaeand 25Pseudomonas aeruginosastrains resistant to fluoroquinolones (including strains with the extended-spectrum β-lactamase [ESBL] phenotype and ceftazidime-resistant strains) collected from our institution. The MICs and mechanisms of resistance to fluoroquinolone were also studied. Ninety-nine percent of fluoroquinolone-resistantEnterobacteriaceaestrains were inhibited at a ceftazidime-avibactam MIC of ≤4 mg/liter (using the susceptible CLSI breakpoint for ceftazidime alone as a reference). Ceftazidime-avibactam was very active against ESBLEscherichia coli(MIC90of 0.25 mg/liter), ESBLKlebsiella pneumoniae(MIC90of 0.5 mg/liter), ceftazidime-resistant AmpC-producing species (MIC90of 1 mg/liter), non-ESBLE. coli(MIC90of ≤0.125 mg/liter), non-ESBLK. pneumoniae(MIC90of 0.25 mg/liter), and ceftazidime-nonresistant AmpC-producing species (MIC90of ≤0.5 mg/liter). Ninety-six percent of fluoroquinolone-resistantP. aeruginosastrains were inhibited at a ceftazidime-avibactam MIC of ≤8 mg/liter (using the susceptible CLSI breakpoint for ceftazidime alone as a reference), with a MIC90of 8 mg/liter. Additionally, fluoroquinolone-resistant mutants from each species tested were obtainedin vitrofrom two strains, one susceptible to ceftazidime and the other a β-lactamase producer with a high MIC against ceftazidime but susceptible to ceftazidime-avibactam. Thereby, the impact of fluoroquinolone resistance on the activity of ceftazidime-avibactam could be assessed. The MIC90values of ceftazidime-avibactam for the fluoroquinolone-resistant mutant strains ofEnterobacteriaceaeandP. aeruginosawere ≤4 mg/liter and ≤8 mg/liter, respectively. We conclude that the presence of fluoroquinolone resistance does not affectEnterobacteriaceaeandP. aeruginosasusceptibility to ceftazidime-avibactam; that is, there is no cross-resistance.

scholarly journals An Improved Medium for Colistin Susceptibility Testing

2018 ◽  
Vol 56 (5) ◽  
Author(s):  
Konrad Gwozdzinski ◽  
Saina Azarderakhsh ◽  
Can Imirzalioglu ◽  
Linda Falgenhauer ◽  
Trinad Chakraborty
Keyword(s):  
Susceptibility Testing ◽  
Acquired Resistance ◽  
Multidrug Resistant ◽  
Colistin Resistance ◽  
Reliable Determination ◽  
Content Type ◽  
E Coli ◽  
Resistant Species ◽  
Mueller Hinton ◽  
Serovar Typhimurium

ABSTRACTThe plasmid-located colistin resistance genemcr-1confers low-level resistance to colistin, a last-line antibiotic against multidrug-resistant Gram-negative bacteria. Current CLSI-EUCAST recommendations require the use of a broth microdilution (BMD) method with cation-adjusted Mueller-Hinton (CA-MH) medium for colistin susceptibility testing, but approximately 15% of all MCR-1 producers are classified as sensitive in that broth. Here we report on an improved calcium-enhanced Mueller-Hinton (CE-MH) medium that permits simple and reliable determination ofmcr-1-containingEnterobacteriaceae. Colistin susceptibility testing was performed for 50mcr-1-containingEscherichia coliandKlebsiella pneumoniaeisolates, 7 intrinsically polymyxin-resistant species,K. pneumoniaeandE. coliisolates with acquired resistance to polymyxins due tomgrBandpmrBmutations, respectively, and 32mcr-1-negative, colistin-susceptible isolates ofAcinetobacter baumannii,Citrobacter freundii,Enterobacter cloacae,E. coli,K. pneumoniae, andSalmonella entericaserovar Typhimurium. A comparison of the colistin MICs determined in CA-MH medium and those obtained in CE-MH medium was performed using both the BMD and strip-based susceptibility test formats. We validated the data using an isogenic IncX4 plasmid lackingmcr-1. Use of the CE-MH broth provides clear separation between resistant and susceptible isolates in both BMD and gradient diffusion assays; this is true for bothmcr-1-containingEnterobacteriaceaeisolates and those exhibiting either intrinsic or acquired colistin resistance. CE-MH medium is simple to prepare and overcomes current problems associated with BMD and strip-based colistin susceptibility testing, and use of the medium is easy to implement in routine diagnostic laboratories, even in resource-poor settings.

scholarly journals Droplet- Rather than Aerosol-Mediated Dispersion Is the Primary Mechanism of Bacterial Transmission from Contaminated Hand-Washing Sink Traps

2018 ◽  
Vol 85 (2) ◽  
Author(s):  
Shireen M. Kotay ◽  
Rodney M. Donlan ◽  
Christine Ganim ◽  
Katie Barry ◽  
Bryan E. Christensen ◽  
...  
Keyword(s):  
Patient Care ◽  
Sampling Methods ◽  
Fluorescent Protein ◽  
Model Organism ◽  
Air Sampling ◽  
Multidrug Resistant ◽  
Hand Washing ◽  
Content Type ◽  
E Coli ◽  
Green Fluorescent

ABSTRACT An alarming rise in hospital outbreaks implicating hand-washing sinks has led to widespread acknowledgment that sinks are a major reservoir of antibiotic-resistant pathogens in patient care areas. An earlier study using green fluorescent protein (GFP)-expressing Escherichia coli (GFP-E. coli) as a model organism demonstrated dispersal from drain biofilms in contaminated sinks. The present study further characterizes the dispersal of microorganisms from contaminated sinks. Replicate hand-washing sinks were inoculated with GFP-E. coli, and dispersion was measured using qualitative (settle plates) and quantitative (air sampling) methods. Dispersal caused by faucet water was captured with settle plates and air sampling methods when bacteria were present on the drain. In contrast, no dispersal was captured without or in between faucet events, amending an earlier theory that bacteria aerosolize from the P-trap and disperse. Numbers of dispersed GFP-E. coli cells diminished substantially within 30 minutes after faucet usage, suggesting that the organisms were associated with larger droplet-sized particles that are not suspended in the air for long periods. IMPORTANCE Among the possible environmental reservoirs in a patient care environment, sink drains are increasingly recognized as a potential reservoir to hospitalized patients of multidrug-resistant health care-associated pathogens. With increasing antimicrobial resistance limiting therapeutic options for patients, a better understanding of how pathogens disseminate from sink drains is urgently needed. Once this knowledge gap has decreased, interventions can be engineered to decrease or eliminate transmission from hospital sink drains to patients. The current study further defines the mechanisms of transmission for bacteria that colonize sink drains.

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

2017 ◽  
Vol 61 (11) ◽  
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.

scholarly journals In VitroActivity of RX-P873 against Enterobacteriaceae, Pseudomonas aeruginosa, and Acinetobacter baumannii

2015 ◽  
Vol 59 (4) ◽  
pp. 2280-2285 ◽  
Author(s):  
Robert K. Flamm ◽  
Paul R. Rhomberg ◽  
Ronald N. Jones ◽  
David J. Farrell
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Acinetobacter Baumannii ◽  
Active Agent ◽  
Multidrug Resistant ◽  
Surveillance Program ◽  
Gram Negative ◽  
Content Type ◽  
Highly Active ◽  
Bacterial Ribosome

ABSTRACTRX-P873 is a novel antibiotic from the pyrrolocytosine series which exhibits high binding affinity for the bacterial ribosome and broad-spectrum antibiotic properties. The pyrrolocytosines have shownin vitroactivity against multidrug-resistant Gram-negative and Gram-positive strains of bacteria known to cause complicated urinary tract, skin, and lung infections, as well as sepsis.Enterobacteriaceae(657),Pseudomonas aeruginosa(200), andAcinetobacter baumannii(202) isolates from North America and Europe collected in 2012 as part of a worldwide surveillance program were testedin vitroby broth microdilution using Clinical and Laboratory Standards Institute (CLSI) methodology. RX-P873 (MIC90, 0.5 μg/ml) was >32-fold more active than ceftazidime and inhibited 97.1% and 99.5% ofEnterobacteriaceaeisolates at MIC values of ≤1 and ≤4 μg/ml, respectively. There were only three isolates with an MIC value of >4 μg/ml (all were indole-positiveProtea). RX-P873 (MIC50/90, 2/4 μg/ml) was highly active againstPseudomonas aeruginosaisolates, including isolates which were nonsusceptible to ceftazidime or meropenem. RX-P873 was 2-fold less active againstP. aeruginosathan tobramycin (MIC90, 2 μg/ml; 91.0% susceptible) and colistin (MIC90, 2 μg/ml; 99.5% susceptible) and 2-fold more potent than amikacin (MIC90, 8 μg/ml; 93.5% susceptible) and meropenem (MIC90, 8 μg/ml; 76.0% susceptible). RX-P873, the most active agent againstAcinetobacter baumannii(MIC90, 1 μg/ml), was 2-fold more active than colistin (MIC90, 2 μg/ml; 97.0% susceptible) and 4-fold more active than tigecycline (MIC90, 4 μg/ml). This novel agent merits further exploration of its potential against multidrug-resistant Gram-negative bacteria.

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