scholarly journals Integron-Located oxa-32 Gene Cassette Encoding an Extended-Spectrum Variant of OXA-2 β-Lactamase from Pseudomonas aeruginosa

2002 ◽  
Vol 46 (2) ◽  
pp. 566-569 ◽  
Author(s):  
Laurent Poirel ◽  
Patrick Gerome ◽  
Christophe De Champs ◽  
Jean Stephanazzi ◽  
Thierry Naas ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Amino Acid ◽  
Clinical Isolate ◽  
Amino Acid Substitution ◽  
Gene Cassette ◽  
Site Directed Mutagenesis ◽  
Directed Mutagenesis ◽  
Class 1 Integron ◽  
Class D ◽  
Class 1

ABSTRACT Pseudomonas aeruginosa clinical isolate CY-1, which was resistant to ceftazidime, harbored a conjugative ca. 250-kb plasmid that contained a class 1 integron with two gene cassettes encoding OXA-32, an OXA-2- type β-lactamase, and the aminoglycoside acetyltransferase AAC(6′)Ib9. OXA-32 differed from OXA-2 by an Leu169Ile amino acid substitution (class D numbering). Site-directed mutagenesis established that Ile169 is responsible for resistance to ceftazidime but not to cefotaxime.

scholarly journals Oxacillinase-Mediated Resistance to Cefepime and Susceptibility to Ceftazidime in Pseudomonas aeruginosa

2001 ◽  
Vol 45 (6) ◽  
pp. 1615-1620 ◽  
Author(s):  
Daniel Aubert ◽  
Laurent Poirel ◽  
Jacqueline Chevalier ◽  
Sophie Leotard ◽  
Jean-Marie Pages ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Amino Acid ◽  
Clinical Isolate ◽  
Amino Acid Identity ◽  
Class 1 Integron ◽  
Acid Identity ◽  
Resistance Phenotype ◽  
Class D ◽  
Class 1 ◽  
Efflux Mechanism

ABSTRACT Pseudomonas aeruginosa clinical isolate SOF-1 was resistant to cefepime and susceptible to ceftazidime. This resistance phenotype was explained by the expression of OXA-31, which shared 98% amino acid identity with a class D β-lactamase, OXA-1. Theoxa-31 gene was located on a ca. 300-kb nonconjugative plasmid and on a class 1 integron. No additional efflux mechanism for cefepime was detected in P. aeruginosa SOF-1. Resistance to cefepime and susceptibility to ceftazidime in P. aeruginosawere conferred by OXA-1 as well.

scholarly journals VIM-19, a Metallo-β-Lactamase with Increased Carbapenemase Activity from Escherichia coli and Klebsiella pneumoniae

2009 ◽  
Vol 54 (1) ◽  
pp. 471-476 ◽  
Author(s):  
Jose-Manuel Rodriguez-Martinez ◽  
Patrice Nordmann ◽  
Nicolas Fortineau ◽  
Laurent Poirel
Keyword(s):  
Escherichia Coli ◽  
Amino Acid ◽  
Klebsiella Pneumoniae ◽  
Hydrolytic Activity ◽  
Site Directed Mutagenesis ◽  
Directed Mutagenesis ◽  
Amino Acid Substitutions ◽  
Class 1 Integron ◽  
Carbapenem Resistant ◽  
Class 1

ABSTRACT Two carbapenem-resistant isolates, one Escherichia coli isolate and one Klebsiella pneumoniae isolate, recovered from an Algerian patient expressed a novel VIM-type metallo-β-lactamase (MBL). The identified bla VIM-19 gene was located on a ca. 160-kb plasmid and located inside a class 1 integron in both isolates. VIM-19 differed from VIM-1 by the Asn215Lys and Ser228Arg substitutions, increasing its hydrolytic activity toward carbapenems. Site-directed mutagenesis experiments showed that both substitutions were necessary for the increased carbapenemase activity of VIM-19. This study indicates that MBLs with enhanced activity toward carbapenems may be obtained as a result of very few amino acid substitutions.

scholarly journals Characterization of Class 1 Integrons from Pseudomonas aeruginosa That Contain the blaVIM-2Carbapenem-Hydrolyzing β-Lactamase Gene and of Two Novel Aminoglycoside Resistance Gene Cassettes

2001 ◽  
Vol 45 (2) ◽  
pp. 546-552 ◽  
Author(s):  
Laurent Poirel ◽  
Thierry Lambert ◽  
Salih Türkoglü ◽  
Esthel Ronco ◽  
Jean-Louis Gaillard ◽  
...  
Keyword(s):  
Amino Acids ◽  
Pseudomonas Aeruginosa ◽  
Amino Acid ◽  
Resistance Gene ◽  
Gene Cassette ◽  
Amino Acid Sequences ◽  
Aminoglycoside Resistance ◽  
Class 1 Integron ◽  
Gene Cassettes ◽  
Class 1

ABSTRACT Two clonally unrelated Pseudomonas aeruginosa clinical strains, RON-1 and RON-2, were isolated in 1997 and 1998 from patients hospitalized in a suburb of Paris, France. Both isolates expressed the class B carbapenem-hydrolyzing β-lactamase VIM-2 previously identified in Marseilles in the French Riviera. In both isolates, thebla VIM-2 cassette was part of a class 1 integron that also encoded aminoglycoside-modifying enzymes. In one case, two novel aminoglycoside resistance gene cassettes,aacA29a and aacA29b, were located at the 5′ and 3′ end of the bla VIM-2 gene cassette, respectively. The aacA29a and aacA29b gene cassettes were fused upstream with a 101-bp part of the 5′ end of theqacE cassette. The deduced amino acid sequence AAC(6′)-29a protein shared 96% identity with AAC(6′)-29b but only 34% identity with the aacA7-encoded AAC(6′)-I1, the closest relative of the AAC(6′)-I family enzymes. These aminoglycoside acetyltransferases had amino acid sequences much shorter (131 amino acids) than the other AAC(6′)-I enzymes (144 to 153 amino acids). They conferred resistance to amikacin, isepamicin, kanamycin, and tobramycin but not to gentamicin, netilmicin, and sisomicin.

scholarly journals Multidrug-Resistant Pseudomonas aeruginosa Strain That Caused an Outbreak in a Neurosurgery Ward and Its aac(6′)-Iae Gene Cassette Encoding a Novel Aminoglycoside Acetyltransferase

2005 ◽  
Vol 49 (9) ◽  
pp. 3734-3742 ◽  
Author(s):  
Jun-ichiro Sekiguchi ◽  
Tsukasa Asagi ◽  
Tohru Miyoshi-Akiyama ◽  
Tomoko Fujino ◽  
Intetsu Kobayashi ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Amino Acid ◽  
Resistance Gene ◽  
Gene Cassette ◽  
Multidrug Resistant ◽  
Aminoglycoside Resistance ◽  
Amino Acid Sequence Level ◽  
Class 1 Integron ◽  
Class 1 ◽  
Tract Infections

ABSTRACT We characterized multidrug-resistant Pseudomonas aeruginosa strains isolated from patients involved in an outbreak of catheter-associated urinary tract infections that occurred in a neurosurgery ward of a hospital in Sendai, Japan. Pulsed-field gel electrophoresis of SpeI-, XbaI-, or HpaI-digested genomic DNAs from the isolates revealed that clonal expansion of a P. aeruginosa strain designated IMCJ2.S1 had occurred in the ward. This strain possessed broad-spectrum resistance to aminoglycosides, β-lactams, fluoroquinolones, tetracyclines, sulfonamides, and chlorhexidine. Strain IMCJ2.S1 showed a level of resistance to some kinds of disinfectants similar to that of a control strain of P. aeruginosa, ATCC 27853. IMCJ2.S1 contained a novel class 1 integron, In113, in the chromosome but not on a plasmid. In113 contains an array of three gene cassettes of bla IMP-1, a novel aminoglycoside resistance gene, and the aadA1 gene. The aminoglycoside resistance gene, designated aac(6′)-Iae, encoded a 183-amino-acid protein that shared 57.1% identity with AAC(6′)-Iq. Recombinant AAC(6′)-Iae protein showed aminoglycoside 6′-N-acetyltransferase activity by thin-layer chromatography. Escherichia coli expressing exogenous aac(6′)-Iae showed resistance to amikacin, dibekacin, isepamicin, kanamycin, netilmicin, sisomicin, and tobramycin but not to arbekacin, gentamicins, or streptomycin. Alterations of gyrA and parC at the amino acid sequence level were detected in IMCJ2.S1, suggesting that such mutations confer the resistance to fluoroquinolones observed for this strain. These results indicate that P. aeruginosa IMCJ2.S1 has developed multidrug resistance by acquiring resistance determinants, including a novel member of the aac(6′)-I family and mutations in drug resistance genes.

scholarly journals OXA-28, an Extended-Spectrum Variant of OXA-10 β-Lactamase from Pseudomonas aeruginosa and Its Plasmid- and Integron-Located Gene

2001 ◽  
Vol 45 (2) ◽  
pp. 447-453 ◽  
Author(s):  
Laurent Poirel ◽  
Delphine Girlich ◽  
Thierry Naas ◽  
Patrice Nordmann
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Amino Acid ◽  
Variable Region ◽  
Gene Cassette ◽  
Cloning And Expression ◽  
Marginal Effect ◽  
Class 1 Integron ◽  
E Coli ◽  
Class 1 ◽  
Lactamase Gene

ABSTRACT Pseudomonas aeruginosa ED-1, isolated from a pulmonary brush of a patient hospitalized in a suburb of Paris, France, was resistant to ceftazidime and of intermediate susceptibility to ureidopenicillins and to cefotaxime. Cloning and expression of the β-lactamase gene content of this isolate in Escherichia coli DH10B identified a novel OXA-10 variant, OXA-28, with a pI value of 8.1 and a molecular mass of 29 kDa. It differed from OXA-10 by 10 amino acid changes and from OXA-13 and OXA-19 by 2 amino acid changes, including a glycine instead of tryptophan at position 164, which is likely involved in its resistance to ceftazidime. Like OXA-11, -14, -16, and -19 and as opposed to OXA-17, OXA-28 predominantly compromised ceftazidime and had only marginal effect on the MICs of aztreonam and cefotaxime in P. aeruginosa. Once expressed in E. coli, OXA-28 raised the MIC of ceftazidime to a much higher level than those of amoxicillin, cephalothin, and cefotaxime (128, 16, 8, and 4 μg/ml, respectively). OXA-28 β-lactamase had a broad spectrum of activity, including ceftazidime. Its activity was partially antagonized by clavulanic acid (50% inhibitory concentration, 10 μM) and NaCl addition. The oxa28 gene cassette was inserted in the variable region of a class 1 integron, In57, immediately downstream of an amino 6′-N-acetyltransferase gene cassette,aac(6′)Ib. The structures of the integrons carrying eitheroxa28, oxa13, or oxa19 gene cassettes were almost identical, suggesting that they may have derived from a common ancestor as a result of the common European origin of theP. aeruginosa isolates. In57 was located on a self-transferable plasmid of ca. 150 kb that was transferred fromP. aeruginosa to P. aeruginosa.

scholarly journals Characterization of a Novel Plasmid-Mediated Cephalosporinase (CMY-9) and Its Genetic Environment in an Escherichia coli Clinical Isolate

2002 ◽  
Vol 46 (8) ◽  
pp. 2427-2434 ◽  
Author(s):  
Yohei Doi ◽  
Naohiro Shibata ◽  
Keigo Shibayama ◽  
Kazunari Kamachi ◽  
Hiroshi Kurokawa ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Amino Acid ◽  
Amino Acid Sequence ◽  
Gene Cassette ◽  
Single Amino Acid ◽  
Common Region ◽  
Class 1 Integron ◽  
Class 1 ◽  
The Common ◽  
High Level

ABSTRACT An Escherichia coli strain, HKYM68, which showed resistance to broad-spectrum cephalosporins was isolated from a sputum specimen in Japan. The high-level resistance of the strain to ceftazidime, cefpirome, and moxalactam was carried by a self-transferable plasmid. The β-lactamase gene responsible for the resistance was cloned and sequenced. The deduced amino acid sequence of this gene product, CMY-9, had a single amino acid substitution (E85D), the residue reported to be part of the recognition site for the R1 side chain of β-lactams, compared with the amino acid sequence of CMY-8 and also had 78% identity with the amino acid sequence of CepH, a chromosomal cephalosporinase of Aeromonas hydrophila. A sul1-type class 1 integron containing an aacA1-orfG gene cassette was identified upstream of bla CMY-9 and ended with a truncated 3′ conserved segment. The following 2.1 kb was almost identical to the common region of integrons In6 and In7 and the integron of pSAL-1, except that orf513 encoding a putative transposase was identified instead of orf341 due to addition of a single nucleotide. bla CMY-9 was closely located downstream of the end of the common region. These observations are indicative of the exogenous derivation of bla CMY-9 from some environmental microorganisms such as aeromonads.

scholarly journals Genetic and Enzymatic Properties of Metallo-β-Lactamase VIM-5 from a Clinical Isolate of Enterobacter cloacae

2005 ◽  
Vol 49 (10) ◽  
pp. 4400-4403 ◽  
Author(s):  
Gulcin G. Gacar ◽  
Kenan Midilli ◽  
Fetiye Kolayli ◽  
Kivanc Ergen ◽  
Sibel Gundes ◽  
...  
Keyword(s):  
Clinical Isolate ◽  
Single Gene ◽  
Enterobacter Cloacae ◽  
Gene Cassette ◽  
Enzymatic Properties ◽  
Class 1 Integron ◽  
Hindiii Fragment ◽  
Clinical Strains ◽  
Class 1

ABSTRACT A VIM-5-producing Enterobacter cloacae isolate (EDV/1) was identified in a collection of clinical strains stored before 2002. The gene, bla VIM-5, was located on a 2,712-bp BamHI-HindIII fragment of a 23-kbp (approximately) nonconjugative plasmid (pEDV5) in a class 1 integron as a single gene cassette.

scholarly journals A Single Amino Acid Substitution in a Mannosyltransferase, WbdA, Converts the Escherichia coli O9 Polysaccharide into O9a: Generation of a New O-Serotype Group

2000 ◽  
Vol 182 (9) ◽  
pp. 2567-2573 ◽  
Author(s):  
Nobuo Kido ◽  
Hidemitsu Kobayashi
Keyword(s):  
Escherichia Coli ◽  
Amino Acid ◽  
Amino Acid Substitution ◽  
Site Directed Mutagenesis ◽  
Single Amino Acid Substitution ◽  
Single Amino Acid ◽  
Directed Mutagenesis ◽  
E Coli ◽  
Chimeric Genes ◽  
Functional Studies

ABSTRACT wbdA is a mannosyltransferase gene that is involved in synthesis of the Escherichia coli O9a polysaccharide, a mannose homopolymer with a repeating unit of 2-αMan-1,2-αMan-1,3-αMan-1,3-αMan-1. The equivalent structural O polysaccharide in the E. coli O9 andKlebsiella O3 strains is 2-αMan-1,2-αMan-1,2-αMan-1,3-αMan-1,3-αMan-1, with an excess of one mannose in the 1,2 linkage. We have cloned wbdAgenes from these O9 and O3 strains and shown by genetic and functional studies that wbdA is the only gene determining the O-polysaccharide structure of O9 or O9a. Based on functional analysis of chimeric genes and site-directed mutagenesis, we showed that a single amino acid substitution, C55R, in WbdA of E. coli O9 converts the O9 polysaccharide into O9a. DNA sequencing revealed the substitution to be conserved in other E. coli O9a strains. The reverse substitution, R55C, in WbdA of E. coli O9a resulted in lipopolysaccharide synthesis showing no ladder profile instead of the conversion of O9a to O9. This suggests that more than one amino acid substitution in WbdA is required for conversion from O9a to O9.

scholarly journals qnrVC-Like Gene Located in a Novel Complex Class 1 Integron Harboring the ISCR1 Element in an Aeromonas punctata Strain from an Aquatic Environment in Shandong Province, China

2010 ◽  
Vol 54 (8) ◽  
pp. 3471-3474 ◽  
Author(s):  
Ruirui Xia ◽  
Xianhu Guo ◽  
Yuzhen Zhang ◽  
Hai Xu
Keyword(s):  
Amino Acid ◽  
Gene Cassette ◽  
Multidrug Resistant ◽  
Amino Acid Identity ◽  
Complex Class ◽  
Class 1 Integron ◽  
Class 1 ◽  
Gyrase A ◽  
Ciprofloxacin Resistance ◽  
Novel Complex

ABSTRACT A qnrVC-like gene, qnrVC4, was found in a novel complex class 1 integron gene cassette array following the ISCR1 element and bla PER-1 in a multidrug-resistant strain of the aquatic bacterium Aeromonas punctata. The deduced QnrVC4 protein sequence shares 45% to 81% amino acid identity with quinolone resistance determinants QnrB6, QnrA1, QnrS1, QnrC, QnrVC1, and QnrVC3. A Ser-83 to Ile amino acid substitution in gyrase A may be mainly responsible for ciprofloxacin resistance in this strain.

scholarly journals Novel Variant (blaVIM-4) of the Metallo-β-Lactamase Gene blaVIM-1 in a Clinical Strain of Pseudomonas aeruginosa

2002 ◽  
Vol 46 (12) ◽  
pp. 4026-4028 ◽  
Author(s):  
Spyros Pournaras ◽  
Athanassios Tsakris ◽  
Maria Maniati ◽  
Leonidas S. Tzouvelekis ◽  
Antonios N. Maniatis
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Amino Acid ◽  
Amino Acid Position ◽  
Clinical Strain ◽  
Nucleotide Difference ◽  
Class 1 Integron ◽  
Class 1 ◽  
Novel Variant ◽  
Lactamase Gene

ABSTRACT A Pseudomonas aeruginosa isolate highly resistant to carbapenems was collected from a patient with postsurgical cerebrospinal infection in Greece. The isolate carried a class 1 integron that contained as a sole cassette the gene bla VIM-4, a novel variant of bla VIM-1, with one nucleotide difference resulting in a Ser-to-Arg change at amino acid position 175 of the VIM-1 enzyme. This is the first detection of a VIM-1 variant after its appearance in Italy.

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