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 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 National Surveillance of Antimicrobial Susceptibility of Bacteremic Gram-Negative Bacteria with Emphasis on Community-Acquired Resistant Isolates: Report from the 2019 Surveillance of Multicenter Antimicrobial Resistance in Taiwan (SMART)

2020 ◽  
Vol 64 (10) ◽  
Author(s):  
Po-Yu Liu ◽  
Yu-Lin Lee ◽  
Min-Chi Lu ◽  
Pei-Lan Shao ◽  
Po-Liang Lu ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Pseudomonas Aeruginosa ◽  
Antimicrobial Resistance ◽  
Klebsiella Pneumoniae ◽  
Gram Negative Bacteria ◽  
National Surveillance ◽  
Gram Negative ◽  
Content Type ◽  
E Coli ◽  
Carbapenem Resistant

ABSTRACT A multicenter collection of bacteremic isolates of Escherichia coli (n = 423), Klebsiella pneumoniae (n = 372), Pseudomonas aeruginosa (n = 300), and Acinetobacter baumannii complex (n = 199) was analyzed for susceptibility. Xpert Carba-R assay and sequencing for mcr genes were performed for carbapenem- or colistin-resistant isolates. Nineteen (67.8%) carbapenem-resistant K. pneumoniae (n = 28) and one (20%) carbapenem-resistant E. coli (n = 5) isolate harbored blaKPC (n = 17), blaOXA-48 (n = 2), and blaVIM (n = 1) genes.

scholarly journals NDM-12, a Novel New Delhi Metallo-β-Lactamase Variant from a Carbapenem-Resistant Escherichia coli Clinical Isolate in Nepal

2014 ◽  
Vol 58 (10) ◽  
pp. 6302-6305 ◽  
Author(s):  
Tatsuya Tada ◽  
Basudha Shrestha ◽  
Tohru Miyoshi-Akiyama ◽  
Kayo Shimada ◽  
Hiroshi Ohara ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Amino Acid ◽  
Clinical Isolate ◽  
Urine Sample ◽  
Enzymatic Activities ◽  
Amino Acid Substitutions ◽  
New Delhi ◽  
Content Type ◽  
Carbapenem Resistant

ABSTRACTA novel New Delhi metallo-β-lactamase variant, NDM-12, was identified in a carbapenem-resistantEscherichia coliclinical isolate obtained from a urine sample from a patient in Nepal. NDM-12 differed from NDM-1 by two amino acid substitutions (M154L and G222D). The enzymatic activities of NDM-12 against β-lactams were similar to those of NDM-1, although NDM-12 showed lowerkcat/Kmratios for all β-lactams tested except doripenem. TheblaNDM-12gene was located in a plasmid of 160 kb.

scholarly journals New Variant of mcr-3 in an Extensively Drug-Resistant Escherichia coli Clinical Isolate Carrying mcr-1 and blaNDM-5

2017 ◽  
Vol 61 (12) ◽  
Author(s):  
Lu Liu ◽  
Yu Feng ◽  
Xiaoxia Zhang ◽  
Alan McNally ◽  
Zhiyong Zong
Keyword(s):  
Escherichia Coli ◽  
Clinical Isolate ◽  
Amino Acid Substitutions ◽  
Drug Resistant ◽  
Content Type ◽  
Carbapenem Resistant ◽  
Resistant Genes ◽  
Extensively Drug Resistant ◽  
New Variant ◽  
Carbapenemase Gene

ABSTRACT A colistin- and carbapenem-resistant Escherichia coli clinical isolate was found to carry two plasmid-borne colistin-resistant genes, mcr-1 and the newly identified mcr-3, and a carbapenemase gene, bla NDM-5. mcr-3 is a new variant (mcr-3.5) in the isolate and encodes three amino acid substitutions compared with the original MCR-3. mcr-3 was carried by a TnAs3-like transposon on a self-transmissible IncP plasmid in the isolate, highlighting that mcr-3 may have widely spread.

scholarly journals Bacterial Two-Hybrid Analysis of Interactions between Region 4 of the ς70 Subunit of RNA Polymerase and the Transcriptional Regulators Rsd from Escherichia coli and AlgQ from Pseudomonas aeruginosa

2001 ◽  
Vol 183 (21) ◽  
pp. 6413-6421 ◽  
Author(s):  
Simon L. Dove ◽  
Ann Hochschild
Keyword(s):  
Gene Expression ◽  
Escherichia Coli ◽  
Pseudomonas Aeruginosa ◽  
Amino Acid ◽  
Rna Polymerase ◽  
Amino Acid Substitution ◽  
Transcriptional Regulators ◽  
Binding Motif ◽  
E Coli ◽  
Two Hybrid

ABSTRACT A number of transcriptional regulators mediate their effects through direct contact with the ς70 subunit ofEscherichia coli RNA polymerase (RNAP). In particular, several regulators have been shown to contact a C-terminal portion of ς70 that harbors conserved region 4. This region of ς contains a putative helix-turn-helix DNA-binding motif that contacts the −35 element of ς70-dependent promoters directly. Here we report the use of a recently developed bacterial two-hybrid system to study the interaction between the putative anti-ς factor Rsd and the ς70 subunit of E. coli RNAP. Using this system, we found that Rsd can interact with an 86-amino-acid C-terminal fragment of ς70 and also that amino acid substitution R596H, within region 4 of ς70, weakens this interaction. We demonstrated the specificity of this effect by showing that substitution R596H does not weaken the interaction between ς and two other regulators shown previously to contact region 4 of ς70. We also demonstrated that AlgQ, a homolog of Rsd that positively regulates virulence gene expression inPseudomonas aeruginosa, can contact the C-terminal region of the ς70 subunit of RNAP from this organism. We found that amino acid substitution R600H in ς70 fromP. aeruginosa, corresponding to the R596H substitution in E. coli ς70, specifically weakens the interaction between AlgQ and ς70. Taken together, our findings suggest that Rsd and AlgQ contact similar surfaces of RNAP present in region 4 of ς70 and probably regulate gene expression through this contact.

scholarly journals Outbreak Caused by NDM-1- and RmtB-Producing Escherichia coli in Bulgaria

2014 ◽  
Vol 58 (4) ◽  
pp. 2472-2474 ◽  
Author(s):  
Laurent Poirel ◽  
Encho Savov ◽  
Arzu Nazli ◽  
Angelina Trifonova ◽  
Iva Todorova ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
16S Rrna ◽  
Sequence Type ◽  
Content Type ◽  
E Coli ◽  
Carbapenem Resistant ◽  
The World ◽  
High Level ◽  
16S Rrna Methylase ◽  
Level Resistance

ABSTRACTTwelve consecutive carbapenem-resistantEscherichia coliisolates were recovered from patients (infection or colonization) hospitalized between March and September 2012 in different units at a hospital in Bulgaria. They all produced the carbapenemase NDM-1 and the extended-spectrum-β-lactamase CTX-M-15, together with the 16S rRNA methylase RmtB, conferring high-level resistance to all aminoglycosides. All those isolates were clonally related and belonged to the same sequence type, ST101. In addition to being the first to identify NDM-producing isolates in Bulgaria, this is the very first study reporting an outbreak of NDM-1-producingE. coliin the world.

scholarly journals Anaerobic Cysteine Degradation and Potential Metabolic Coordination in Salmonella enterica and Escherichia coli

2017 ◽  
Vol 199 (16) ◽  
Author(s):  
Melissa Loddeke ◽  
Barbara Schneider ◽  
Tamiko Oguri ◽  
Iti Mehta ◽  
Zhenyu Xuan ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Amino Acid ◽  
Salmonella Enterica ◽  
Acid Synthesis ◽  
Lower Growth ◽  
Amino Acid Synthesis ◽  
Content Type ◽  
E Coli ◽  
Sulfur Containing ◽  
Sulfur Containing Compounds

ABSTRACT Salmonella enterica has two CyuR-activated enzymes that degrade cysteine, i.e., the aerobic CdsH and an unidentified anaerobic enzyme; Escherichia coli has only the latter. To identify the anaerobic enzyme, transcript profiling was performed for E. coli without cyuR and with overexpressed cyuR. Thirty-seven genes showed at least 5-fold changes in expression, and the cyuPA (formerly yhaOM) operon showed the greatest difference. Homology suggested that CyuP and CyuA represent a cysteine transporter and an iron-sulfur-containing cysteine desulfidase, respectively. E. coli and S. enterica ΔcyuA mutants grown with cysteine generated substantially less sulfide and had lower growth yields. Oxygen affected the CyuR-dependent genes reciprocally; cyuP-lacZ expression was greater anaerobically, whereas cdsH-lacZ expression was greater aerobically. In E. coli and S. enterica, anaerobic cyuP expression required cyuR and cysteine and was induced by l-cysteine, d-cysteine, and a few sulfur-containing compounds. Loss of either CyuA or RidA, both of which contribute to cysteine degradation to pyruvate, increased cyuP-lacZ expression, which suggests that CyuA modulates intracellular cysteine concentrations. Phylogenetic analysis showed that CyuA homologs are present in obligate and facultative anaerobes, confirming an anaerobic function, and in archaeal methanogens and bacterial acetogens, suggesting an ancient origin. Our results show that CyuA is the major anaerobic cysteine-catabolizing enzyme in both E. coli and S. enterica, and it is proposed that anaerobic cysteine catabolism can contribute to coordination of sulfur assimilation and amino acid synthesis. IMPORTANCE Sulfur-containing compounds such as cysteine and sulfide are essential and reactive metabolites. Exogenous sulfur-containing compounds can alter the thiol landscape and intracellular redox reactions and are known to affect several cellular processes, including swarming motility, antibiotic sensitivity, and biofilm formation. Cysteine inhibits several enzymes of amino acid synthesis; therefore, increasing cysteine concentrations could increase the levels of the inhibited enzymes. This inhibition implies that control of intracellular cysteine levels, which is the immediate product of sulfide assimilation, can affect several pathways and coordinate metabolism. For these and other reasons, cysteine and sulfide concentrations must be controlled, and this work shows that cysteine catabolism contributes to this control.

scholarly journals The Topology of the l-Arginine Exporter ArgO Conforms to an Nin-CoutConfiguration in Escherichia coli: Requirement for the Cytoplasmic N-Terminal Domain, Functional Helical Interactions, and an Aspartate Pair for ArgO Function

2016 ◽  
Vol 198 (23) ◽  
pp. 3186-3199 ◽  
Author(s):  
Amit Pathania ◽  
Arvind Kumar Gupta ◽  
Swati Dubey ◽  
Balasubramanian Gopal ◽  
Abhijit A. Sardesai
Keyword(s):  
Escherichia Coli ◽  
Amino Acid ◽  
Cytoplasmic Membrane ◽  
Basic Amino Acid ◽  
Intramolecular Interactions ◽  
Membrane Topology ◽  
Content Type ◽  
E Coli ◽  
Terminal Domain

ABSTRACTArgO and LysE are members of the LysE family of exporter proteins and ordinarily mediate the export ofl-arginine (Arg) inEscherichia coliandl-lysine (Lys) and Arg inCorynebacterium glutamicum, respectively. Under certain conditions, ArgO also mediates Lys export. To delineate the arrangement of ArgO in the cytoplasmic membrane ofE. coli, we have employed a combination of cysteine accessibilityin situ, alkaline phosphatase fusion reporters, and protein modeling to arrive at a topological model of ArgO. Our studies indicate that ArgO assumes an Nin-Coutconfiguration, potentially forming a five-transmembrane helix bundle flanked by a cytoplasmic N-terminal domain (NTD) comprising roughly its first 38 to 43 amino acyl residues and a short periplasmic C-terminal region (CTR). Mutagenesis studies indicate that the CTR, but not the NTD, is dispensable for ArgO functionin vivoand that a pair of conserved aspartate residues, located near the opposing edges of the cytoplasmic membrane, may play a pivotal role in facilitating transmembrane Arg flux. Additional studies on amino acid substitutions that impair ArgO functionin vivoand their derivatives bearing compensatory amino acid alterations indicate a role for intramolecular interactions in the Arg export mechanism, and some interactions are corroborated by normal-mode analyses. Lastly, our studies suggest that ArgO may exist as a monomerin vivo, thus highlighting the requirement for intramolecular interactions in ArgO, as opposed to interactions across multiple ArgO monomers, in the formation of an Arg-translocating conduit.IMPORTANCEThe orthologous proteins LysE ofC. glutamicumand ArgO ofE. colifunction as exporters of the basic amino acidsl-arginine andl-lysine and the basic amino acidl-arginine, respectively, and LysE can functionally substitute for ArgO when expressed inE. coli. Notwithstanding this functional equivalence, studies reported here show that ArgO possesses a membrane topology that is distinct from that reported for LysE, with substantial variation in the topological arrangement of the proximal one-third portions of the two exporters. Additional genetic andin silicostudies reveal the importance of (i) the cytoplasmic N-terminal domain, (ii) a pair of conserved aspartate residues, and (iii) potential intramolecular interactions in ArgO function and indicate that an Arg-translocating conduit is formed by a monomer of ArgO.

scholarly journals Emergence of Colistin Resistance Gene mcr-1 in Cronobacter sakazakii Producing NDM-9 and in Escherichia coli from the Same Animal

2016 ◽  
Vol 61 (2) ◽  
Author(s):  
Bao-Tao Liu ◽  
Feng-Jing Song ◽  
Ming Zou ◽  
Zhi-Hui Hao ◽  
Hu Shan
Keyword(s):  
Escherichia Coli ◽  
Resistance Gene ◽  
Resistance Genes ◽  
Cronobacter Sakazakii ◽  
Colistin Resistance ◽  
Content Type ◽  
E Coli ◽  
Carbapenem Resistant

ABSTRACT We report the presence of mcr-1 in Escherichia coli and carbapenem-resistant Cronobacter sakazakii from the same diseased chicken. The mcr-1 gene linked with ISApl1 was located on two different IncI2 plasmids, including one multidrug plasmid in E. coli, whereas fosA3-bla NDM-9 was on an IncB/O plasmid in C. sakazakii. The development of the fosA3-bla NDM-9 resistance region was mediated by IS26. The colocation of mcr-1 or bla NDM-9 with other resistance genes will accelerate the dissemination of the two genes.

scholarly journals Carbapenem and colistin-resistant bacteria in North Lebanon: Coexistence of mcr-1 and NDM-4 genes in Escherichia coli

2021 ◽  
Vol 15 (07) ◽  
pp. 934-342
Author(s):  
Charbel Al-Bayssari ◽  
Tania Nawfal Dagher ◽  
Samar El Hamoui ◽  
Fadi Fenianos ◽  
Nehman Makdissy ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Pseudomonas Aeruginosa ◽  
Resistance Genes ◽  
Multidrug Resistant ◽  
Resistant Bacteria ◽  
Ionization Time ◽  
E Coli ◽  
Flight Mass Spectrometry ◽  
Carbapenem Resistant ◽  
The Matrix

Introduction: The increasing incidence of infections caused by multidrug-resistant bacteria is considered a global health problem. This study aimed to investigate this resistance in Gram-negative bacteria isolated from patients hospitalized in North-Lebanon. Methodology: All isolates were identified using the matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. Antibiotic susceptibility testing was achieved using disk diffusion, E-test and Broth microdilution methods. Phenotypic detection of carbapenemase was carried out using the CarbaNP test. RT-PCR, standard-PCR and sequencing were performed to detect resistance genes and oprD gene. Conjugal transfer was carried out between our isolates and Escherichia coli J53 to detect the genetic localization of resistance genes. MLST was conducted to determine the genotype of each isolate. Results: Twenty-three carbapenem-resistant Enterobacterales of which eight colistin-resistant Escherichia coli, and Twenty carbapenem-resistant Pseudomonas aeruginosa were isolated. All isolates showed an imipenem MIC greater than 32 mg/mL with MICs for colistin greater than 2 mg/L for E. coli isolates. All the Enterobacterales isolates had at least one carbapenemase-encoding gene, with E. coli isolates coharboring blaNDM-4 and mcr-1 genes. Moreover, 16/20 Pseudomonas aeruginosa harbored the blaVIM-2 gene and 18/20 had mutations in the oprD gene. MLST revealed that the isolates belonged to several clones. Conclusions: We report here the first description in the world of clinical E. coli isolates coharboring blaNDM-4 and mcr-1 genes, and K. pneumoniae isolates producing NDM-6 and OXA-48 carbapenemases. Also, we describe the emergence of NDM-1-producing E. cloacae in Lebanon. Screening for these isolates is necessary to limit the spread of resistant microorganisms in hospitals.

Sign in / Sign up

Export Citation Format

Share Document