scholarly journals Genetic and Biochemical Characterization of an Acquired Subgroup B3 Metallo-β-Lactamase Gene,blaAIM-1, and Its Unique Genetic Context in Pseudomonas aeruginosa from Australia

2012 ◽  
Vol 56 (12) ◽  
pp. 6154-6159 ◽  
Author(s):  
Dongeun Yong ◽  
Mark A. Toleman ◽  
Jan Bell ◽  
Brett Ritchie ◽  
Rachael Pratt ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Southern Hybridization ◽  
Biochemical Characterization ◽  
Gene Bank ◽  
Clinical Isolates ◽  
Gram Negative ◽  
Content Type ◽  
Lactamase Gene ◽  
Genetic Context

ABSTRACTThree clinicalPseudomonas aeruginosaisolates (WCH2677, WCH2813, and WCH2837) isolated from the Women's and Children's Hospital, Adelaide, Australia, produced a metallo-β-lactamase (MBL)-positive Etest result. All isolates were PCR negative for known MBL genes. A gene bank was created, and an MBL gene, designatedblaAIM-1, was cloned and fully characterized. The encoded enzyme, AIM-1, is a group B3 MBL that has the highest level of identity to THIN-B and L1. It is chromosomal and flanked by two copies (one intact and one truncated) of an ISCRelement, ISCR15. Southern hybridization studies indicated the movement of both ISCR15andblaAIM-1within the three different clinical isolates. AIM-1 hydrolyzes most β-lactams, with the exception of aztreonam and, to a lesser extent, ceftazidime; however, it possesses significantly higherkcatvalues for cefepime and carbapenems than most other MBLs. AIM-1 was the first mobile group B3 enzyme detected and signals further problems for already beleaguered antimicrobial regimes to treat seriousP. aeruginosaand other Gram-negative infections.

scholarly journals Retrospective Molecular Analysis of DIM-1 Metallo-β-Lactamase Discovered in Pseudomonas stutzeri from India in 2000

2013 ◽  
Vol 58 (1) ◽  
pp. 596-598 ◽  
Author(s):  
Lalitagauri M. Deshpande ◽  
Ronald N. Jones ◽  
Leah N. Woosley ◽  
Mariana Castanheira
Keyword(s):  
Molecular Analysis ◽  
Pseudomonas Stutzeri ◽  
Clinical Isolates ◽  
Gram Negative ◽  
Content Type ◽  
Environmental Source ◽  
Lactamase Gene ◽  
Encoding Genes

ABSTRACTAmong 220 clinical isolates of Gram-negative bacilli collected in India during 2000, 22 strains showing elevated imipenem MICs were evaluated for carbapenemase production. One DIM-1-producingPseudomonas stutzeriisolate was detected, and no other carbapenemase-encoding genes were identified. This detection of a DIM-1-producingP. stutzeriisolate from India predating the finding of this gene in the index Dutch strain and the very recent detection of DIM-1 in Africa suggest an unidentified environmental source of this metallo-β-lactamase gene.

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

2018 ◽  
Vol 62 (5) ◽  
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 .

scholarly journals Tn6249, a New Tn6162Transposon Derivative Carrying a Double-Integron Platform and Involved with Acquisition of theblaVIM-1Metallo-β-Lactamase Gene in Pseudomonas aeruginosa

2014 ◽  
Vol 59 (3) ◽  
pp. 1583-1587 ◽  
Author(s):  
Vincenzo Di Pilato ◽  
Simona Pollini ◽  
Gian Maria Rossolini
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Genomic Island ◽  
Mercury Resistance ◽  
Original Structure ◽  
Content Type ◽  
Lactamase Gene ◽  
Genetic Context ◽  
Generation Sequencing ◽  
Index Strain

ABSTRACTThe In70.2 integron platform appears to be a conserved structure involved in the dissemination of theblaVIM-1metallo-β-lactamase gene inPseudomonas aeruginosa. The genetic context of the In70.2 integron platform fromP. aeruginosaVR-143/97, the VIM-1-producing index strain isolated in Italy in 1997, was fully characterized by a next-generation sequencing approach refined by conventional sequencing. The In70.2 integron platform from VR-143/97 was found to be associated with a defective Tn402-like transposon inserted into theurf2gene of a Tn3family transposon of an original structure, named Tn6249, which also carried a partially deletedmeroperon and an In90 integron platform in a tail-to-tail orientation. Tn6249was inserted into a PACS171b-like genomic island, which was in turn inserted into theendAgene of thePseudomonaschromosomal backbone. Tn6249showed a similar structure and a conserved location with respect to that of Tn6060, a Tn3family transposon associated with In70.2 and carrying a double-integron platform, which was detected in a VIM-1-producingP. aeruginosastrain isolated in Australia in 2008. Both Tn6249and Tn6060are apparently derived from Tn6162, a mercury resistance transposon carrying an integron platform, which was found inP. aeruginosaisolates from different geographic locations. The conservation of the genetic context of Tn6249and Tn6060suggests anin situevolution of these elements after the insertion of a Tn6162-like ancestor into the PACS171b-like genomic island (GI) present in the genome of a successful widespreadP. aeruginosaclonal lineage.

Characterization of saccharolytic nonfermentative bacteria associated with man

1970 ◽  
Vol 16 (5) ◽  
pp. 351-362 ◽  
Author(s):  
M. J. Pickett ◽  
Margaret M. Pedersen
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Pseudomonas Putida ◽  
Pseudomonas Fluorescens ◽  
Pseudomonas Stutzeri ◽  
Clinical Isolates ◽  
Gram Negative ◽  
Clinical Strains ◽  
Pseudomonas Maltophilia ◽  
Reference Strains

Features of 378 clinical isolates of saccharolytic, nonfermentative Gram-negative rods and 20 reference strains were examined. All but four of the clinical strains were assigned to recognized taxa, namely Acinetobacter, Chromobacterium, Flavobacterium, Pseudomonas aeruginosa, Pseudomonas fluorescens, Pseudomonas maltophilia, Pseudomonas multivorans, Pseudomonas putida, Pseudomonas stutzeri, and Xanthomonas.

scholarly journals Genetic and Biochemical Characterization of FRI-1, a Carbapenem-Hydrolyzing Class A β-Lactamase from Enterobacter cloacae

2015 ◽  
Vol 59 (12) ◽  
pp. 7420-7425 ◽  
Author(s):  
Laurent Dortet ◽  
Laurent Poirel ◽  
Samia Abbas ◽  
Saoussen Oueslati ◽  
Patrice Nordmann
Keyword(s):  
Biochemical Characterization ◽  
Enterobacter Cloacae ◽  
Conjugative Plasmid ◽  
Lower Sensitivity ◽  
Gene Encoding ◽  
Content Type ◽  
Class A ◽  
Encoding Gene ◽  
Lactamase Gene

ABSTRACTAnEnterobacter cloacaeisolate was recovered from a rectal swab from a patient hospitalized in France with previous travel to Switzerland. It was resistant to penicillins, narrow- and broad-spectrum cephalosporins, aztreonam, and carbapenems but remained susceptible to expanded-spectrum cephalosporins. Whereas PCR-based identification of the most common carbapenemase genes failed, the biochemical Carba NP test II identified an Ambler class A carbapenemase. Cloning experiments followed by sequencing identified a gene encoding a totally novel class A carbapenemase, FRI-1, sharing 51 to 55% amino acid sequence identity with the closest carbapenemase sequences. However, it shared conserved residues as a source of carbapenemase activity. Purified β-lactamase FRI-1 hydrolyzed penicillins, aztreonam, and carbapenems but spared expanded-spectrum cephalosporins. The 50% inhibitory concentrations (IC50s) of clavulanic acid and tazobactam were 10-fold higher than those found forKlebsiella pneumoniaecarbapenemase (KPC), IMI, and SME, leading to lower sensitivity of FRI-1 activity to β-lactamase inhibitors. TheblaFRI-1gene was located on a ca. 110-kb untypeable, transferable, and non-self-conjugative plasmid. A putative LysR family regulator-encoding gene at the 5′ end of the β-lactamase gene was identified, leading to inducible expression of theblaFRI-1gene.

scholarly journals Identification and Biochemical Characterization of a Novel Protein Phosphatase 2C-Like Ser/Thr Phosphatase in Escherichia coli

2018 ◽  
Vol 200 (18) ◽  
Author(s):  
Krithika Rajagopalan ◽  
Elizabeth Nagle ◽  
Jonathan Dworkin
Keyword(s):  
Escherichia Coli ◽  
Protein Phosphatase ◽  
Biochemical Characterization ◽  
Regulatory Protein ◽  
Negative Bacterium ◽  
Gram Negative ◽  
Content Type ◽  
E Coli ◽  
Novel Protein

Regulatory protein phosphorylation is a conserved mechanism of signaling in all biological systems. Recent phosphoproteomic analyses of phylogenetically diverse bacteria, including the model Gram-negative bacteriumEscherichia coli, demonstrate that many proteins are phosphorylated on serine or threonine residues. In contrast to phosphorylation on histidine or aspartate residues, phosphorylation of serine and threonine residues is stable and requires the action of a partner Ser/Thr phosphatase to remove the modification. Although a number of Ser/Thr kinases have been reported inE. coli, no partner Ser/Thr phosphatases have been identified. Here, we biochemically characterize a novel Ser/Thr phosphatase that acts to dephosphorylate a Ser/Thr kinase that is encoded in the same operon.

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

2020 ◽  
Vol 64 (7) ◽  
Author(s):  
José Manuel Ortiz de la Rosa ◽  
Patrice Nordmann ◽  
Laurent Poirel
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Genomic Island ◽  
Multidrug Resistant ◽  
Resistance Mechanisms ◽  
Genomic Islands ◽  
Clinical Isolates ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
Content Type ◽  
Genes Encoding

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.

scholarly journals In Vitro Activity of Cefepime-Zidebactam, Ceftazidime-Avibactam, and Other Comparators against Clinical Isolates of Enterobacterales, Pseudomonas aeruginosa, and Acinetobacter baumannii: Results from China Antimicrobial Surveillance Network (CHINET) in 2018

2020 ◽  
Vol 65 (1) ◽  
pp. e01726-20
Author(s):  
Yang Yang ◽  
Yan Guo ◽  
Dandan Yin ◽  
Yonggui Zheng ◽  
Shi Wu ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Acinetobacter Baumannii ◽  
Clinical Isolates ◽  
Surveillance Network ◽  
Gram Negative ◽  
Content Type ◽  
Highly Active ◽  
Carbapenem Resistant ◽  
Almost All

ABSTRACTThis study evaluated the in vitro activity of cefepime-zidebactam in comparison with that of ceftazidime-avibactam and other comparators against clinically significant Gram-negative bacillus isolates. A total of 3,400 nonduplicate Gram-negative clinical isolates were collected from 45 medical centers across China in the CHINET Program in 2018, including Enterobacterales (n = 2,228), Pseudomonas aeruginosa (n = 657), and Acinetobacter baumannii (n = 515). The activities of cefepime-zidebactam and 20 comparators were determined by broth microdilution as recommended by the Clinical and Laboratory Standards Institute. Cefepime-zidebactam demonstrated potent activity against almost all Enterobacterales (MIC50/90, 0.125/1 mg/liter) and good activity against P. aeruginosa (MIC50/90, 2/8 mg/liter). Among the 373 carbapenem-resistant Enterobacteriaceae isolates, 57.3% (213/373) and 15.3% (57/373) were positive for blaKPC-2 and blaNDM, respectively. Cefepime-zidebactam showed a MIC of ≤2 mg/liter for 92.0% (196/213) of blaKPC-2 producers and 79.7% (47/59) of blaNDM producers. Ceftazidime-avibactam showed good in vitro activity against Enterobacterales (MIC50/90, 0.25/2 mg/liter; 94.0% susceptible) and P. aeruginosa (MIC50/90, 4/16 mg/liter; 86.9% susceptible). Ceftazidime-avibactam was active against 9.1% of carbapenem-resistant Escherichia coli isolates (63.6% were blaNDM producers) and 84.6% of Klebsiella pneumoniae isolates (74.3% were blaKPC producers). Most (90.1%) blaKPC-2 producers were susceptible to ceftazidime-avibactam. Cefepime-zidebactam demonstrated limited activity (MIC50/90, 16/32 mg/liter) against the 515 A. baumannii isolates (79.2% were carbapenem resistant), and ceftazidime-avibactam was less active (MIC50/90, 64/>64 mg/liter). Cefepime-zidebactam was highly active against clinical isolates of Enterobacterales and P. aeruginosa, including blaKPC-2-positive Enterobacterales and blaNDM-positive Enterobacterales and carbapenem-resistant P. aeruginosa. And ceftazidime-avibactam was highly active against blaKPC-2-positive Enterobacterales and carbapenem-resistant P. aeruginosa.

scholarly journals Complex Structure of Pseudomonas aeruginosa Arginine Rhamnosyltransferase EarP with Its Acceptor Elongation Factor P

2019 ◽  
Vol 201 (13) ◽  
Author(s):  
Chao He ◽  
Ning Liu ◽  
Fudong Li ◽  
Xiaoyu Jia ◽  
Hui Peng ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Conformational Changes ◽  
Biochemical Characterization ◽  
Complex Structure ◽  
Elongation Factor ◽  
Titration Calorimetry ◽  
Content Type ◽  
Elongation Factor P

ABSTRACT A bacterial inverting glycosyltransferase EarP transfers rhamnose from dTDP-β-l-rhamnose (TDP-Rha) to Arg32 of translation elongation factor P (EF-P) to activate its function. We report here the structural and biochemical characterization of Pseudomonas aeruginosa EarP. In contrast to recently reported Neisseria meningitidis EarP, P. aeruginosa EarP exhibits differential conformational changes upon TDP-Rha and EF-P binding. Sugar donor binding enhances acceptor binding to EarP, as revealed by structural comparison between the apo-, TDP-Rha-, and TDP/EF-P-bound forms and isothermal titration calorimetry experiments. In vitro EF-P rhamnosylation combined with active-site geometry indicates that Asp16 corresponding to Asp20 of N. meningitidis EarP is the catalytic base, whereas Glu272 is another putative catalytic residue. Our study should provide the basis for EarP-targeted inhibitor design against infections from P. aeruginosa and other clinically relevant species. IMPORTANCE Posttranslational rhamnosylation of EF-P plays a key role in Pseudomonas aeruginosa, establishing virulence and antibiotic resistance, as well as survival. The detailed structural and biochemical characterization of the EF-P-specific rhamnosyltransferase EarP from P. aeruginosa not only demonstrates that sugar donor TDP-Rha binding enhances acceptor EF-P binding to EarP but also should provide valuable information for the structure-guided development of its inhibitors against infections from P. aeruginosa and other EarP-containing pathogens.

scholarly journals A Novel VIM-Type Metallo-β-Lactamase Variant, VIM-60, with Increased Hydrolyzing Activity against Fourth-Generation Cephalosporins in Pseudomonas aeruginosa Clinical Isolates in Japan

2019 ◽  
Vol 63 (6) ◽  
Author(s):  
Tomomi Hishinuma ◽  
Tatsuya Tada ◽  
Hiroki Uchida ◽  
Masahiro Shimojima ◽  
Teruo Kirikae
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Amino Acid ◽  
Multidrug Resistant ◽  
Clinical Isolates ◽  
Fourth Generation ◽  
Amino Acid Substitutions ◽  
Content Type ◽  
Catalytic Activities ◽  
Genetic Context

ABSTRACT A novel VIM-type metallo-β-lactamase variant, VIM-60, was identified in multidrug-resistant Pseudomonas aeruginosa clinical isolates in Japan. Compared with VIM-2, VIM-60 had two amino acid substitutions (Arg228Leu and His252Arg) and higher catalytic activities against fourth-generation cephalosporins. The genetic context for blaVIM-60 was intI1-blaVIM-60-aadA1-aacA31-qacEdeltaI-sulI on the chromosome.

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