scholarly journals New Variant of CTX-M-Type Extended-Spectrum β-Lactamases, CTX-M-71, with a Gly238Cys Substitution in a Klebsiella pneumoniae Isolate from Bulgaria

2009 ◽  
Vol 53 (10) ◽  
pp. 4518-4521 ◽  
Author(s):  
Ines Schneider ◽  
Anne Marie Queenan ◽  
Rumyana Markovska ◽  
Boyka Markova ◽  
Emma Keuleyan ◽  
...  
Keyword(s):  
Amino Acid ◽  
Klebsiella Pneumoniae ◽  
Amino Acid Substitution ◽  
Hydrolytic Activity ◽  
Extended Spectrum ◽  
New Variant

ABSTRACT A single K lebsiella pneumoniae strain isolated in a Bulgarian hospital was found to produce CTX-M-71, a new CTX-M variant characterized by one amino acid substitution from glycine to cysteine at position 238 in comparison to CTX-M-15. This exchange decreased the hydrolytic activity of the β-lactamase for cefotaxime, ceftazidime, and cefepime.

scholarly journals Typing of SHV Extended-Spectrum β-Lactamases by Pyrosequencing in Klebsiella pneumoniae Strains with Chromosomal SHV β-Lactamase

2008 ◽  
Vol 52 (7) ◽  
pp. 2632-2635 ◽  
Author(s):  
Marjo Haanperä ◽  
Sofia D. Forssten ◽  
Pentti Huovinen ◽  
Jari Jalava
Keyword(s):  
Amino Acid ◽  
Klebsiella Pneumoniae ◽  
Dna Sequence ◽  
Reliable Method ◽  
Molecular Detection ◽  
Beta Lactamases ◽  
Extended Spectrum

ABSTRACT In Klebsiella pneumoniae, the cooccurrence of chromosomal and plasmid-mediated beta-lactamases can hinder their accurate molecular detection. We developed a fast and reliable method that allows the typing of isolates carrying more than one SHV gene. The method is based on pyrosequencing the DNA sequence corresponding to amino acid positions 35, 238, and 240.

scholarly journals Diversity of TEM Mutants in Proteus mirabilis

1999 ◽  
Vol 43 (11) ◽  
pp. 2671-2677 ◽  
Author(s):  
R. Bonnet ◽  
C. De Champs ◽  
D. Sirot ◽  
C. Chanal ◽  
R. Labia ◽  
...  
Keyword(s):  
Amino Acid ◽  
Amino Acid Substitution ◽  
Proteus Mirabilis ◽  
Clinical Isolates ◽  
Amino Acid Substitutions ◽  
First Report ◽  
Conjugative Plasmids ◽  
Extended Spectrum ◽  
Nucleotide Mutation

ABSTRACT In a survey of resistance to amoxicillin among clinical isolates ofProteus mirabilis, 10 TEM-type β-lactamases were characterized: (i) the well-known penicillinases TEM-1 and TEM-2, the extended-spectrum β-lactamases (ESBLs) TEM-3 and TEM-24, and the inhibitor-resistant TEM (IRT) TEM-44 and (ii) five novel enzymes, a penicillinase TEM-57 similar to TEM-1, an ESBL TEM-66 similar to TEM-3, and three IRTs, TEM-65, TEM-73, and TEM-74. The penicillinase TEM-57 and the ESBL TEM-66 differed from TEM-1 and TEM-3, respectively, by the amino acid substitution Gly-92→Asp (nucleotide mutation G-477→A). This substitution could have accounted for the decrease in pIs (5.2 for TEM-57 and 6.0 for TEM-66) but did not necessarily affect the intrinsic activities of these enzymes. The IRT TEM-65 was an IRT-1-like IRT (Cys-244) related to TEM-2 (Lys-39). The two other IRTs, TEM-73 and TEM-74, were related to IRT-1 (Cys-244) and IRT-2 (Ser-244), respectively, and harbored the amino acid substitutions Leu-21→Phe and Thr-265→Met. In this study, the ESBLs TEM-66, TEM-24, and TEM-3 were encoded by large (170- to 180-kb) conjugative plasmids that exhibited similar patterns after digestion and hybridization with the TEM and AAC(6′)I probes. The three IRTs TEM-65, TEM-73, and TEM-74 were encoded by plasmids that ranged in size from 42 to 70 kb but for which no transfer was obtained. The characterization of five new plasmid-mediated TEM-type β-lactamases and the first report of TEM-24 in P. mirabilis are evidence of the wide diversity of β-lactamases produced in this species and of its possible role as a β-lactamase-encoding plasmid reservoir.

scholarly journals TEM-89 β-Lactamase Produced by a Proteus mirabilis Clinical Isolate: New Complex Mutant (CMT 3) with Mutations in both TEM-59 (IRT-17) and TEM-3

2001 ◽  
Vol 45 (12) ◽  
pp. 3591-3594 ◽  
Author(s):  
Catherine Neuwirth ◽  
Stephanie Madec ◽  
Eliane Siebor ◽  
Andre Pechinot ◽  
Jean-Marie Duez ◽  
...  
Keyword(s):  
Amino Acid ◽  
Clinical Isolate ◽  
Amino Acid Substitution ◽  
Proteus Mirabilis ◽  
Hydrolytic Activity ◽  
Single Amino Acid Substitution ◽  
Single Amino Acid ◽  
Clinical Strain ◽  
Almost All

ABSTRACT TEM-89 (CMT-3) is the first complex mutant β-lactamase produced by a clinical strain of Proteus mirabilis (strain Pm 631). This new enzyme, which has a pI of 6.28, is derived from TEM-3 and has a single amino acid substitution also encountered in TEM-59 (inhibitor-resistant TEM β-lactamase IRT-17): Ser-130 to Gly. TEM-89 hydrolyzed penicillins to the same extent that TEM-3 did but lost almost all hydrolytic activity for cephalosporins and, like TEM-59, was highly resistant to inhibitors.

scholarly journals Acquisition of Extended-Spectrum β-Lactamase GES-6 Leading to Resistance to Ceftolozane-Tazobactam Combination in Pseudomonas aeruginosa

2018 ◽  
Vol 63 (1) ◽  
Author(s):  
Laurent Poirel ◽  
José-Manuel Ortiz De La Rosa ◽  
Nicolas Kieffer ◽  
Véronique Dubois ◽  
Aurélie Jayol ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Amino Acid ◽  
Hydrolytic Activity ◽  
Sequence Type ◽  
Effective Alternative ◽  
Amino Acid Substitutions ◽  
Content Type ◽  
Extended Spectrum

ABSTRACT A clinical Pseudomonas aeruginosa isolate resistant to all β-lactams, including ceftolozane-tazobactam and carbapenems, was recovered. It belonged to sequence type 235 and produced the extended-spectrum β-lactamase (ESBL) GES-6 differing from GES-1 by two amino acid substitutions (E104K and G170S). GES-6 possessed an increased hydrolytic activity toward carbapenems and to ceftolozane and a decreased susceptibility to β-lactamase inhibitors compared to GES-1, except for avibactam. We show here that resistance to ceftolozane-tazobactam may occur through acquisition of a specific ESBL in P. aeruginosa but that ceftazidime-avibactam combination remains an effective alternative.

scholarly journals Novel Plasmid-Encoded Class C β-Lactamase (MOX-2) in Klebsiella pneumoniae from Greece

2002 ◽  
Vol 46 (7) ◽  
pp. 2262-2265 ◽  
Author(s):  
Laurent Raskine ◽  
Isabelle Borrel ◽  
Guilène Barnaud ◽  
Sophie Boyer ◽  
Béatrice Hanau-Berçot ◽  
...  
Keyword(s):  
Amino Acid ◽  
Klebsiella Pneumoniae ◽  
Hydrolytic Activity ◽  
Amino Acid Sequences ◽  
Clinical Strain ◽  
Aeromonas Sobria ◽  
Class C

ABSTRACT Klebsiella pneumoniae KOL, a clinical strain resistant to various β-lactams, was isolated from the stools of a patient from Greece. This strain harbored a new pI 9.1 plasmid-mediated AmpC β-lactamase with unusually high levels of hydrolytic activity for cefoxitin and cefotetan that we named MOX-2. Sequencing of bla MOX-2 revealed 93.2, 92.9, 92.7, and 73.1% identities with the deduced amino acid sequences of CMY-8, MOX-1, CMY-1, and the AmpC β-lactamase of Aeromonas sobria, respectively.

scholarly journals Evaluation of a new variant in the aggrecan gene potentially associated with chondrodysplastic dwarfism in Miniature horses

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Danilo Giorgi Abranches de Andrade ◽  
Roberta Martins Basso ◽  
Angelo José Magro ◽  
Renée Laufer-Amorim ◽  
Alexandre Secorun Borges ◽  
...  
Keyword(s):  
Genetic Testing ◽  
Amino Acid ◽  
Amino Acid Substitution ◽  
Autosomal Recessive ◽  
Autosomal Recessive Disorder ◽  
Dwarf Phenotype ◽  
Horse Genome ◽  
Complex Interactions ◽  
New Variant ◽  
Exon 11

Abstract Chondrodysplastic dwarfism in Miniature horses is an autosomal recessive disorder previously associated with four mutations (D1, D2, D3*, and D4) in the aggrecan (ACAN) gene. The aim of this study was to identify additional variants in the candidate ACAN gene associated with chondrodysplastic dwarfism in Miniature horses. Fifteen dwarf Miniature horses were found to possess only one of the dwarfism-causing variants, and two possessed none of the variants. The ACAN exons (EquCab3.0) of seven dwarf Miniature horses were sequenced. A missense SNP in coding exon 11 (g.95271115A > T, c.6465A > T—RefSeq XM_005602799.2), which resulted in the amino acid substitution p.Leu2155Phe (RefSeq XP_005602856.2), was initially associated with the dwarf phenotype. The variant was tested and found present in 14 dwarf foals as well as one parent of each, and both parents of a dwarf possessing two copies. Genetic testing of 347 phenotypically normal Miniature horses demonstrated that none had more than one of the dwarf alleles or c.6465A > T. However, a study of large breeds revealed the presence of c.6465A > T, which was present in homozygosis in two Mangalarga Marchador horses. We suggest that c.6465A > T as a marker of disequilibrium or complex interactions in the Miniature horse genome could contribute to the associated dwarfism.

scholarly journals Ceftazidime-Resistant EnterobacteriaceaeIsolates from Three Polish Hospitals: Identification of Three Novel TEM- and SHV-5-Type Extended-Spectrum β-Lactamases

1998 ◽  
Vol 42 (3) ◽  
pp. 514-520 ◽  
Author(s):  
Marek Gniadkowski ◽  
Ines Schneider ◽  
Renate Jungwirth ◽  
Waleria Hryniewicz ◽  
Adolf Bauernfeind
Keyword(s):  
Escherichia Coli ◽  
Amino Acid ◽  
Klebsiella Pneumoniae ◽  
Detailed Analysis ◽  
Amino Acid Substitutions ◽  
New Combinations ◽  
Extended Spectrum ◽  
The Family ◽  
Genetic Events ◽  
Esbl Producers

ABSTRACT Twelve ceftazidime-resistant isolates of the familyEnterobacteriaceae (11 Klebsiella pneumoniaeisolates and 1 Escherichia coli isolate) were collected in 1995 from three Polish hospitals located in different cities. All were identified as producers of extended-spectrum β-lactamases (ESBLs). Detailed analysis of their β-lactamase contents revealed that six of them expressed SHV-5-like ESBLs. The remaining six were found to produce three different TEM enzymes, each characterized by a pI value of 6.0 and specified by new combinations of amino acid substitutions. The amino acid substitutions compared to the TEM-1 β-lactamase sequence were Gly238Ser, Glu240Lys, and Thr265Met for TEM-47; Leu21Phe, Gly238Ser, Glu240Lys, and Thr265Met for TEM-48; and Leu21Phe, Gly238Ser, Glu240Lys, Thr265Met, and Ser268Gly for TEM-49. The new TEM β-lactamases, TEM-47, TEM-48, and TEM-49, belong to a subfamily of TEM-2-related enzymes. Genes coding for TEM-47 and TEM-49 could have originated from the TEM-48-encoding sequence by various single genetic events. The new TEM derivatives probably document the already advanced microevolution of ESBLs ongoing in Polish hospitals, in a majority of which no monitoring of ESBL producers was performed before 1996.

scholarly journals Characterization of TEM-56, a Novel β-Lactamase Produced by a Klebsiella pneumoniae Clinical Isolate

2000 ◽  
Vol 44 (2) ◽  
pp. 453-455 ◽  
Author(s):  
Catherine Neuwirth ◽  
Roger Labia ◽  
Eliane Siebor ◽  
Andre Pechinot ◽  
Stephanie Madec ◽  
...  
Keyword(s):  
Amino Acid ◽  
Klebsiella Pneumoniae ◽  
Amino Acid Sequence ◽  
Clinical Isolate ◽  
Isoelectric Point ◽  
Catalytic Properties ◽  
Resistance Level ◽  
Extended Spectrum ◽  
Moderate Resistance

ABSTRACT TEM-56 produced by a Klebsiella pneumoniae clinical isolate is a novel β-lactamase of isoelectric point 6.4 that confers a moderate resistance level to expanded-spectrum cephalosporins. The amino acid sequence deduced from the corresponding bla gene showed two amino acid replacements with respect to the TEM-2 sequence: Glu-104 to Lys and His-153 to Arg. This enzyme showed catalytic properties close to those of TEM-18. Thus, TEM-56 appears as a new TEM mutant, an intermediary between TEM-18 and the extended-spectrum β-lactamase TEM-21.

scholarly journals NDM-4 Metallo-β-Lactamase with Increased Carbapenemase Activity from Escherichia coli

2012 ◽  
Vol 56 (4) ◽  
pp. 2184-2186 ◽  
Author(s):  
Patrice Nordmann ◽  
Anne E. Boulanger ◽  
Laurent Poirel
Keyword(s):  
Escherichia Coli ◽  
Amino Acid ◽  
Amino Acid Substitution ◽  
Active Sites ◽  
Hydrolytic Activity ◽  
Single Amino Acid Substitution ◽  
Single Amino Acid ◽  
Amino Acid Substitutions ◽  
Content Type

ABSTRACTA clinicalEscherichia coliisolate resistant to all β-lactams, including carbapenems, expressed a novel metallo-β-lactamase (MBL), NDM-4, differing from NDM-1 by a single amino acid substitution (Met154Leu). NDM-4 possessed increased hydrolytic activity toward carbapenems and several cephalosporins compared to that of NDM-1. This amino acid substitution was not located in the known active sites of NDM-1, indicating that remote amino acid substitutions might also play a role in the extended activity of this MBL.

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