scholarly journals Molecular Characterization of OXA-20, a Novel Class D β-Lactamase, and Its Integron from Pseudomonas aeruginosa

1998 ◽  
Vol 42 (8) ◽  
pp. 2074-2083 ◽  
Author(s):  
Thierry Naas ◽  
Wladimir Sougakoff ◽  
Anne Casetta ◽  
Patrice Nordmann
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Amino Acid ◽  
Clavulanic Acid ◽  
Antibiotic Resistance Gene ◽  
Amino Acid Identity ◽  
Acid Identity ◽  
Class D ◽  
Acid Protein ◽  
Amino Acid Protein

ABSTRACT The Pseudomonas aeruginosa Mus clinical isolate produces OXA-18, a pI 5.5 class D extended-spectrum β-lactamase totally inhibited by clavulanic acid (L. N. Philippon, T. Naas, A.-T. Bouthors, V. Barakett, and P. Nordmann, Antimicrob. Agents Chemother. 41:2188–2195, 1997). A second β-lactamase was cloned, and the recombinant Escherichia coli clone pPL10 expressed a pI 7.4 β-lactamase which conferred high levels of amoxicillin and ticarcillin resistance and which was partially inhibited by clavulanic acid. The 2.5-kb insert from pPL10 was sequenced, and a 266-amino-acid protein (OXA-20) was deduced; this protein has low amino acid identity with most of the class D β-lactamases except OXA-2, OXA-15, and OXA-3 (75% amino acid identity with each). OXA-20 is a restricted-spectrum oxacillinase and is unusually inhibited by clavulanic acid. OXA-20 is a peculiar β-lactamase because its translation initiates with a TTG (leucine) codon, which is rarely used as a translational origin in bacteria. Exploration of the genetic environment of oxa20revealed the presence of the following integron features: (i) a second antibiotic resistance gene, aacA4; (ii) anintI1 gene; and (iii) two 59-base elements, each associated with either oxa20 or aacA4. This integron is peculiar because it lacks the 3′ conserved region, and therefore is not a sul1-associated integron like most of them, and because its 3′ end is located within tnpR, a gene involved in the transposition of Tn5393, a gram-negative transposon.P. aeruginosa Mus produces two novel and unrelated oxacillinases, OXA-18 and OXA-20, both of which are inhibited by clavulanic acid.

scholarly journals Characterization of a Naturally Occurring Class D β-Lactamase from Achromobacter xylosoxidans

2008 ◽  
Vol 52 (6) ◽  
pp. 1952-1956 ◽  
Author(s):  
Yohei Doi ◽  
Laurent Poirel ◽  
David L. Paterson ◽  
Patrice Nordmann
Keyword(s):  
Amino Acid ◽  
Amino Acid Identity ◽  
Burkholderia Cenocepacia ◽  
Achromobacter Xylosoxidans ◽  
Acid Identity ◽  
Low Level ◽  
Narrow Spectrum ◽  
Naturally Occurring ◽  
Class D

ABSTRACT A chromosomally encoded class D β-lactamase, OXA-114, was characterized from Achromobacter xylosoxidans strain CIP69598. β-Lactamase OXA-114 shared 56% amino acid identity with the naturally occurring class D β-lactamase of Burkholderia cenocepacia and 42% identity with the acquired oxacillinases OXA-9 and OXA-18. OXA-114 has a narrow-spectrum hydrolysis profile, although it includes imipenem, at a very low level. PCR and sequencing revealed that bla OXA-114-like genes were identified in all A. xylosoxidans strains tested (n = 5), indicating that this β-lactamase is naturally occurring in that species. Induction experiments with imipenem and cefoxitin did not show inducibility of bla OXA-114 expression.

Sequence and characterization of a novel chromosomal aminoglycoside phosphotransferase gene, aph (3')-IIb, in Pseudomonas aeruginosa.

1996 ◽  
Vol 40 (5) ◽  
pp. 1254-1256 ◽  
Author(s):  
H Hächler ◽  
P Santanam ◽  
F H Kayser
Keyword(s):  
Amino Acids ◽  
Pseudomonas Aeruginosa ◽  
Amino Acid ◽  
Amino Acid Identity ◽  
Open Reading Frames ◽  
Acid Identity ◽  
Aminoglycoside Phosphotransferase ◽  
Psti Fragment ◽  
Reading Frames

A novel, probably chromosomally encoded, aminoglycoside phosphotransferase gene was cloned on a 2,996-bp PstI fragment from Pseudomonas aeruginosa and designated aph (3')-IIb. It coded for a protein of 268 amino acids that showed 51.7% amino acid identity with APH (3')-II [APH(3') is aminoglycoside-3' phosphotransferase] from Tn5. Two other open reading frames on the cloned fragment showed homology to a signal-transducing system in P. aeruginosa.

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 Characterization of the Gallate Dioxygenase Gene: Three Distinct Ring Cleavage Dioxygenases Are Involved in Syringate Degradation by Sphingomonas paucimobilis SYK-6

2005 ◽  
Vol 187 (15) ◽  
pp. 5067-5074 ◽  
Author(s):  
Daisuke Kasai ◽  
Eiji Masai ◽  
Keisuke Miyauchi ◽  
Yoshihiro Katayama ◽  
Masao Fukuda
Keyword(s):  
Amino Acid ◽  
Amino Acid Sequences ◽  
Terminal Region ◽  
Ring Cleavage ◽  
Sphingomonas Paucimobilis ◽  
Acid Protein ◽  
Demethylation Pathway ◽  
Dioxygenase Gene ◽  
Amino Acid Protein

ABSTRACT Sphingomonas paucimobilis SYK-6 converts vanillate and syringate to protocatechuate (PCA) and 3-O-methylgallate (3MGA) in reactions with the tetrahydrofolate-dependent O-demethylases LigM and DesA, respectively. PCA is further degraded via the PCA 4,5-cleavage pathway, whereas 3MGA is metabolized via three distinct pathways in which PCA 4,5-dioxygenase (LigAB), 3MGA 3,4-dioxygenase (DesZ), and 3MGA O-demethylase (LigM) are involved. In the 3MGA O-demethylation pathway, LigM converts 3MGA to gallate, and the resulting gallate appears to be degraded by a dioxygenase other than LigAB or DesZ. Here, we isolated the gallate dioxygenase gene, desB, which encodes a 418-amino-acid protein with a molecular mass of 46,843 Da. The amino acid sequences of the N-terminal region (residues 1 to 285) and the C-terminal region (residues 286 to 418) of DesB exhibited ca. 40% and 27% identity with the sequences of the PCA 4,5-dioxygenase β and α subunits, respectively. DesB produced in Escherichia coli was purified and was estimated to be a homodimer (86 kDa). DesB specifically attacked gallate to generate 4-oxalomesaconate as the reaction product. The Km for gallate and the V max were determined to be 66.9 ± 9.3 μM and 42.7 ± 2.4 U/mg, respectively. On the basis of the analysis of various SYK-6 mutants lacking the genes involved in syringate degradation, we concluded that (i) all of the three-ring cleavage dioxygenases are involved in syringate catabolism, (ii) the pathway involving LigM and DesB plays an especially important role in the growth of SYK-6 on syringate, and (iii) DesB and LigAB are involved in gallate degradation.

Heterologous Expression and Characterization of Tyrosine Decarboxylase from Enterococcus faecalis R612Z1 and Enterococcus faecium R615Z1

2014 ◽  
Vol 77 (4) ◽  
pp. 592-598 ◽  
Author(s):  
FANG LIU ◽  
WENJUAN XU ◽  
LIHUI DU ◽  
DAOYING WANG ◽  
YONGZHI ZHU ◽  
...  
Keyword(s):  
Amino Acid ◽  
Heterologous Expression ◽  
Molecular Mass ◽  
Enterococcus Faecalis ◽  
Enterococcus Faecium ◽  
Maximal Activity ◽  
Tyrosine Decarboxylase ◽  
Acid Protein ◽  
Amino Acid Protein

Tyrosine decarboxylase (TDC) is responsible for tyramine production and can catalyze phenylalanine to produce β-phenylethylamine. Enterococcus strains are a group of bacteria predominantly producing tyramine and β-phenylethylamine in water-boiled salted duck. In this study, the heterologous expression and characterization of two TDCs from Enterococcus faecalis R612Z1 (612TDC) and Enterococcus faecium R615Z1 (615TDC) were studied. The recombinant putative proteins of 612TDC and 615TDC were heterologously expressed in Escherichia coli. 612TDC is a 620-amino-acid protein with a molecular mass of 70.0 kDa, whereas 615TDC is a 625-amino-acid protein with a molecular mass of 70.3 kDa. Both 612TDC and 615TDC showed an optimum temperature of 25°C for the tyrosine and phenylalanine substrates. However, 612TDC revealed maximal activity at pH 5.5, whereas 615TDC revealed maximal activity at pH 6.0. Kinetic studies showed that 612TDC and 615TDC exhibited higher specificity for tyrosine than for phenylalanine. The catalysis abilities of both 612TDC and 615TDC for phenylalanine were restrained significantly with the increase in NaCl concentration, but this was not the case for tyrosine. This study revealed that the enzyme properties of the purified recombinant 612TDC and 615TDC were similar, although their amino acid sequences had 84% identity.

scholarly journals Chromosome-Encoded Ambler Class D β-Lactamase of Shewanella oneidensis as a Progenitor of Carbapenem-Hydrolyzing Oxacillinase

2004 ◽  
Vol 48 (1) ◽  
pp. 348-351 ◽  
Author(s):  
Laurent Poirel ◽  
Claire Héritier ◽  
Patrice Nordmann
Keyword(s):  
Escherichia Coli ◽  
Amino Acid ◽  
Klebsiella Pneumoniae ◽  
Reference Strain ◽  
Shewanella Oneidensis ◽  
Amino Acid Identity ◽  
Gram Negative ◽  
Acid Identity ◽  
Class D ◽  
Lactamase Gene

ABSTRACT A chromosome-encoded β-lactamase gene from a Shewanella oneidensis reference strain was cloned and expressed in Escherichia coli. It encoded a carbapenem-hydrolyzing Ambler class D β-lactamase, OXA-54, that shared 92% amino acid identity with the plasmid-encoded carbapenem-hydrolyzing oxacillinase OXA-48 from Klebsiella pneumoniae. This work suggests that Shewanella spp. may produce the progenitor of oxacillinases compromising the efficacy of imipenem in clinically relevant gram-negative pathogens.

scholarly journals Characterization of a DivergentvanD-Type Resistance Element from the First Glycopeptide-Resistant Strain of Enterococcus faeciumIsolated in Brazil

2000 ◽  
Vol 44 (12) ◽  
pp. 3444-3446 ◽  
Author(s):  
Libera M. Dalla Costa ◽  
Peter E. Reynolds ◽  
Helena A. P. H. M. Souza ◽  
Dilair C. Souza ◽  
Marie-France I. Palepou ◽  
...  
Keyword(s):  
Amino Acid ◽  
Resistant Strain ◽  
Enterococcus Faecium ◽  
Amino Acid Identity ◽  
Open Reading Frame ◽  
Glycopeptide Resistance ◽  
Reading Frame ◽  
Acid Identity ◽  
Resistance Phenotype

ABSTRACT Enterococcus faecium 10/96A from Brazil was resistant to vancomycin (MIC, 256 μg/ml) but gave no amplification products with primers specific for known van genotypes. A 2,368-bp fragment of a van cluster contained one open reading frame encoding a peptide with 83% amino acid identity to VanHD, and a second encoding a d-alanine-d-lactate ligase with 83 to 85% identity to VanD. The divergent glycopeptide resistance phenotype was designated VanD4.

scholarly journals Occurrence and Molecular Characterization of Three Pineapple Mealybug Wilt-Associated Viruses in Pineapple in Taiwan

Plant Disease ◽  
2009 ◽  
Vol 93 (2) ◽  
pp. 196-196 ◽  
Author(s):  
B. N. Shen ◽  
Y. X. Zheng ◽  
W. H. Chen ◽  
T. Y. Chang ◽  
H.-M. Ku ◽  
...  
Keyword(s):  
Amino Acid ◽  
Molecular Characterization ◽  
Amino Acid Identity ◽  
Rt Pcr ◽  
Acid Identity ◽  
Cp Gene ◽  
Mealybug Wilt ◽  
Pineapple Mealybug Wilt ◽  
Pineapple Mealybug

Pineapple (Ananas comosus) is one of the major fruit crops in Taiwan, accounting for 275 million U.S. dollars in 2006, following betel nut and citrus production in crop value. Tainung No. 17 is the most important cultivar, accounting for more than 70% of pineapples planted. Mealybug wilt of pineapple (MWP) is one of the most destructive diseases of pineapple. Pineapple mealybug wilt-associated virus-1 (PMWaV-1), PMWaV-2, and PMWaV-3 were identified as three distinct species in Ampelovirus from diseased Hawaiian pineapple (1,2). In November of 2007, pineapples (cv. Tainung No. 17) planted in Pingtung County of southern Taiwan showed symptoms similar to MWP. Mealybugs (Dysmicoccus brevipes) were also found. Three primer pairs, 225/226, 223/224, and 263/264 described previously specific for the HSP70h genes of PMWaV-1 (1), -2, and -3 (2), respectively, were used to detect the presence of these three viruses by reverse transcription (RT)-PCR. Expected DNA fragments of 590, 610, and 499 nt were obtained from the total RNA isolated from the leaves of diseased pineapples with primer pairs 225/226, 223/224, and 263/264, respectively. The RT-PCR amplified fragments were cloned, sequenced, and analyzed. The 590-nt fragment (Accession No. EU769113) shared 91.6 to 99.5% nucleotide and 96.8 to 99.5% amino acid identity to those of five isolates of PMWaV-1 available in the GenBank; one each from Hawaii (Accession No. AF414119) and Thailand (Accession No. EF620774) and three from Australia (Accession Nos. EF488752, EF467923, and EF467925). The 610-nt fragment (Accession No. EU769115) showed 98.7 and 99.7% nucleotide and 98% and 100% amino acid identity to those of PMWaV-2 from Hawaii (Accession No. AF283103) and Thailand (Accession No. EU016675), respectively. The 499-nt fragment (Accession No. FJ209047) shared 86.8 to 99.0% nucleotide and 94.0 to 100.0% amino acid identity to those of five PMWaV-3 isolates available in the GenBank; one from Hawaii (Accession No. DQ399259) and four from Australia (Accession Nos. EF467918, EF467919, EF488754, and EF488755). Using primer pairs FJ08-1 (5′-ATGGCTGATTCGAGC)/FJ08-2 (5′-TTATTTGCGTCCACC), FJ08-7 (5′-AGTGAGATTGATCGT)/FJ08-8 (5′-TGCAGGTATCCGCTG), and FJ08-35 (5′-AACGACCGAACTCGC)/FJ08-36 (5′-ATACTACAGATATTG) specific to the coat protein (CP) genes of PMWaV-1, -2, and -3, respectively, expected DNA fragments of 774, 909, and 789 nt were amplified by RT-PCR. The 774-nt CP gene of PMWaV-1 (Accession No. EU769114) shared 99% nucleotide and 98.4% amino acid identity to those of Hawaiian isolate (Accession No. AF414119). The 909-nt CP gene of PMWaV-2 (Accession No. EU769116) shared 99.0 and 99.1% nucleotide identity with isolates from Hawaii (Accession No. AF283103) and Cuba (Accession No. DQ225114), respectively, and 99.3% amino acid identity with both. The 789-nt CP gene of PMWaV-3 (Accession No. FJ209048) shared 99.1% nucleotide and 98.1% amino acid identity to those of the Hawaiian isolate (Accession No. DQ399259). One to two viruses among PMWaV-1, -2, and -3 were detected in all 40 samples collected from diseased pineapples. To our knowledge, this is the first report to identify three PMWaVs in the most important and widely planted pineapple cultivar in Taiwan, Tainung No. 17, by molecular characterization of the HSP70h and CP genes. References: (1) D. M. Sether et al. Plant Dis. 85:856, 2001. (2) D. M. Sether et al. Plant Dis. 89:450, 2005.

scholarly journals Molecular and Biochemical Characterization of a Novel Class A β-Lactamase (HER-1) from Escherichia hermannii

2003 ◽  
Vol 47 (8) ◽  
pp. 2669-2673 ◽  
Author(s):  
Anne Beauchef-Havard ◽  
Guillaume Arlet ◽  
Valerie Gautier ◽  
Roger Labia ◽  
Patrick Grimont ◽  
...  
Keyword(s):  
Amino Acid ◽  
Broad Spectrum ◽  
Aeromonas Hydrophila ◽  
Biochemical Characterization ◽  
Amino Acid Identity ◽  
Acid Identity ◽  
Low Level ◽  
Class A ◽  
Moderate Susceptibility

ABSTRACT Escherichia hermannii showed a low level of resistance to amoxicillin and ticarcillin, reversed by clavulanate, and a moderate susceptibility to piperacillin but was susceptible to all cephalosporins. A bla gene was cloned and encoded a typical class A β-lactamase (HER-1, pI 7.5), which shares 45, 44, 41, and 40% amino acid identity with other β-lactamases, AER-1 from Aeromonas hydrophila, MAL-1/Cko-1 from Citrobacter koseri, and TEM-1 and LEN-1, respectively. No ampR gene was detected. Only penicillins were efficiently hydrolyzed, and no hydrolysis was observed for cefuroxime and broad-spectrum cephalosporins. Sequencing of the bla gene in 12 other strains showed 98 to 100% identity with bla HER-1.

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