scholarly journals New Gene Cassettes for Trimethoprim Resistance,dfr13, and Streptomycin-Spectinomycin Resistance,aadA4, Inserted on a Class 1 Integron

2000 ◽  
Vol 44 (2) ◽  
pp. 355-361 ◽  
Author(s):  
Peter V. Adrian ◽  
Christopher J. Thomson ◽  
Keith P. Klugman ◽  
Sebastian G. B. Amyes
Keyword(s):  
Resistance Gene ◽  
Dihydrofolate Reductase ◽  
Antibiotic Resistance Genes ◽  
Amino Acid Identity ◽  
Aminoglycoside Resistance ◽  
Class 1 Integron ◽  
Spectinomycin Resistance ◽  
Class 1 ◽  
Dihydrofolate Reductases ◽  
A Site

ABSTRACT In a previous survey of 357 trimethoprim-resistant isolates of aerobic gram-negative bacteria from commensal fecal flora, hybridization experiments showed that 25% (90 of 357) of the isolates failed to hybridize to specific oligonucleotide probes for dihydrofolate reductase types 1, 2b, 3, 5, 6, 7, 8, 9, 10, and 12. Subsequent cloning and sequencing of a plasmid-borne trimethoprim resistance gene from one of these isolates revealed a new dihydrofolate reductase gene, dfr13, which occurred as a cassette integrated in a site-specific manner in a class 1 integron. The gene product shared 84% amino acid identity with dfr12 and exhibited a trimethoprim inhibition profile similar to that ofdfr12. Gene probing experiments with an oligonucleotide probe specific for this gene showed that 12.3% (44 of 357) of the isolates which did not hybridize to probes for other dihydrofolate reductases hybridized to this probe. Immediately downstream ofdfr13, a new cassette, an aminoglycoside resistance gene of the class AADA [ANT(3")(9)-I], which encodes streptomycin-spectinomycin resistance, was identified. This gene shares 57% identity with the consensus aadA1(ant(3")-Ia) and has been called aadA4(ant(3")-Id). The 3′ end of the aadA4 cassette was truncated by IS26, which was contiguous with a truncated form of Tn3. On the same plasmid, pUK2381, a second copy of IS26 was associated with sul2, which suggests that both integrase and transposase activities have played major roles in the arrangement and dissemination of antibiotic resistance genesdfr13, aadA4, bla TEM-1, and sul2.

scholarly journals New Trimethoprim-Resistant Dihydrofolate Reductase Cassette, dfrXV, Inserted in a Class 1 Integron

1998 ◽  
Vol 42 (9) ◽  
pp. 2221-2224 ◽  
Author(s):  
Peter V. Adrian ◽  
Mignon du Plessis ◽  
Keith P. Klugman ◽  
Sebastian G. B. Amyes
Keyword(s):  
Dihydrofolate Reductase ◽  
Gene Cassette ◽  
Amino Acid Identity ◽  
Type I ◽  
Class 1 Integron ◽  
Reductase Gene ◽  
Sulfonamide Resistance ◽  
Class 1 ◽  
New Gene ◽  
A Site

ABSTRACT The nucleotide sequence of a plasmid-borne trimethoprim resistance gene from a commensal fecal Escherichia coli isolate revealed a new dihydrofolate reductase gene, dfrXV, which occurred as a gene cassette integrated in a site-specific manner in a class 1 integron. The new gene shows 84% nucleotide identity and the predicted protein shows 90% amino acid identity withdfrI and DHFR type I, respectively. Genes for spectinomycin resistance, aadA1 [ant (3′′)-Ia], and sulfonamide resistance, sulI, were located downstream of dfrXV in a manner identical to that in pLMO229.

scholarly journals Class 1 Integron-Associated Tobramycin-Gentamicin Resistance in Campylobacter jejuni Isolated from the Broiler Chicken House Environment

2002 ◽  
Vol 46 (11) ◽  
pp. 3660-3664 ◽  
Author(s):  
Margie D. Lee ◽  
Susan Sanchez ◽  
Martha Zimmer ◽  
Umelaalim Idris ◽  
Mark E. Berrang ◽  
...  
Keyword(s):  
Resistance Gene ◽  
Campylobacter Jejuni ◽  
Broiler Chicken ◽  
Aminoglycoside Resistance ◽  
Class 1 Integron ◽  
Integrase Gene ◽  
Conserved Sequence ◽  
Chicken House ◽  
Class 1 ◽  
Gentamicin Resistance

ABSTRACT Using PCR, we screened 105 isolates of poultry-associated Campylobacter jejuni for the presence of class 1 integrons. Of those isolates, 21% (22 of 105) possessed the integrase gene, but only 5 isolates produced an amplicon in a 5′-3′ conserved sequence PCR directed toward amplification of the resistance cassettes. DNA sequencing demonstrated that all five isolates possessed the aminoglycoside resistance gene, aacA4.

scholarly journals Incidence, Distribution, and Spread of Tetracycline Resistance Determinants and Integron-Associated Antibiotic Resistance Genes among Motile Aeromonads from a Fish Farming Environment

2001 ◽  
Vol 67 (12) ◽  
pp. 5675-5682 ◽  
Author(s):  
Anja S. Schmidt ◽  
Morten S. Bruun ◽  
Inger Dalsgaard ◽  
Jens L. Larsen
Keyword(s):  
Antibiotic Resistance ◽  
Resistance Gene ◽  
Resistance Genes ◽  
Antibiotic Resistance Genes ◽  
Tetracycline Resistance ◽  
Class 1 Integron ◽  
Gene Cassettes ◽  
Class 1 Integrons ◽  
Resistance Determinants ◽  
Class 1

ABSTRACT A collection of 313 motile aeromonads isolated at Danish rainbow trout farms was analyzed to identify some of the genes involved in high levels of antimicrobial resistance found in a previous field trial (A. S. Schmidt, M. S. Bruun, I. Dalsgaard, K. Pedersen, and J. L. Larsen, Appl. Environ. Microbiol. 66:4908–4915, 2000), the predominant resistance phenotype (37%) being a combined oxytetracycline (OTC) and sulphadiazine/trimethoprim resistance. Combined sulphonamide/trimethoprim resistance (135 isolates) appeared closely related to the presence of a class 1 integron (141 strains). Among the isolates containing integrons, four different combinations of integrated resistance gene cassettes occurred, in all cases including a dihydrofolate reductase gene and a downstream aminoglycoside resistance insert (87 isolates) and occasionally an additional chloramphenicol resistance gene cassette (31 isolates). In addition, 23 isolates had “empty” integrons without inserted gene cassettes. As far as OTC resistance was concerned, only 66 (30%) out of 216 resistant aeromonads could be assigned to resistance determinant class A (19 isolates), D (n = 6), or E (n = 39); three isolates contained two tetracycline resistance determinants (AD, AE, and DE). Forty OTC-resistant isolates containing large plasmids were selected as donors in a conjugation assay, 27 of which also contained a class 1 integron. Out of 17 successful R-plasmid transfers to Escherichia coli recipients, the respective integrons were cotransferred along with the tetracycline resistance determinants in 15 matings. Transconjugants were predominantly tetApositive (10 of 17) and contained class 1 integrons with two or more inserted antibiotic resistance genes. While there appeared to be a positive correlation between conjugative R-plasmids andtetA among the OTC-resistant aeromonads, tetEand the unclassified OTC resistance genes as well as class 1 integrons were equally distributed among isolates with and without plasmids. These findings indicate the implication of other mechanisms of gene transfer besides plasmid transfer in the dissemination of antibiotic resistance among environmental motile aeromonads.

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 Characterization of an Integron Carrying blaIMP-1 and a New Aminoglycoside Resistance Gene, aac(6′)-31, and Its Dissemination among Genetically Unrelated Clinical Isolates in a Brazilian Hospital

2007 ◽  
Vol 51 (7) ◽  
pp. 2611-2614 ◽  
Author(s):  
Rodrigo E. Mendes ◽  
Mariana Castanheira ◽  
Mark A. Toleman ◽  
Helio S. Sader ◽  
Ronald N. Jones ◽  
...  
Keyword(s):  
Antimicrobial Resistance ◽  
Pseudomonas Putida ◽  
Resistance Gene ◽  
Clinical Isolate ◽  
Hospitalized Patients ◽  
Aminoglycoside Resistance ◽  
Class 1 Integron ◽  
Resistance Determinants ◽  
Class 1

ABSTRACT Seven bla IMP-1-harboring Acinetobacter sp. isolates and one Pseudomonas putida clinical isolate were recovered from hospitalized patients. All isolates possessed a class 1 integron, named In86, carrying the same cassette array [bla IMP1, aac(6′)-31, and aadA1], which was plasmid located in five of the isolates. This report describes the ability of nonfermentative nosocomial pathogens to acquire and disseminate antimicrobial resistance determinants.

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 Emergence of Plasmid-Mediated Quinolone Resistance in Escherichia coli in Europe

2005 ◽  
Vol 49 (1) ◽  
pp. 71-76 ◽  
Author(s):  
Hedi Mammeri ◽  
Marc Van De Loo ◽  
Laurent Poirel ◽  
Luis Martinez-Martinez ◽  
Patrice Nordmann
Keyword(s):  
Escherichia Coli ◽  
Topoisomerase Ii ◽  
Antibiotic Resistance Genes ◽  
Quinolone Resistance ◽  
Conjugative Plasmid ◽  
Aminoglycoside Resistance ◽  
Class 1 Integron ◽  
Promoter Sequences ◽  
E Coli ◽  
Class 1

ABSTRACT Although quinolone resistance results mostly from chromosomal mutations, it may also be mediated by a plasmid-encoded qnr gene in members of the family Enterobacteriaceae. Thus, 297 nalidixic-acid resistant strains of 2,700 Escherichia coli strains that had been isolated at the Bicêtre Hospital (Le Kremlin-Bicêtre, France) in 2003 were screened for qnr by PCR. A single E. coli isolate that carried a ca. 180-kb conjugative plasmid encoding a qnr determinant was identified. It conferred low-level resistance to quinolones and was associated with a chromosomal mutation in subunit A of the topoisomerase II gene. The qnr gene was located on a sul1-type class 1 integron just downstream of a conserved region (CR) element (CR1) comprising the Orf513 recombinase. Promoter sequences for qnr expression overlapped the extremity of CR1, indicating the role of CR1 in the expression of antibiotic resistance genes. This integron was different from other qnr-positive sul1-type integrons identified in American and Chinese enterobacterial isolates. In addition, plasmid pQR1 carried another class 1 integron that was identical to In53 from E. coli. The latter integron possessed a series of gene cassettes, including those coding for the extended-spectrum β-lactamase VEB-1, the rifampin ADP ribosyltransferase ARR-2, and several aminoglycoside resistance markers. This is the first report of plasmid-mediated quinolone resistance in Europe associated with an unknown level of plasmid-mediated multidrug resistance in Enterobacteriaceae.

scholarly journals Novel Streptomycin and Spectinomycin Resistance Gene as a Gene Cassette within a Class 1 Integron Isolated fromEscherichia coli

1999 ◽  
Vol 43 (12) ◽  
pp. 3036-3038 ◽  
Author(s):  
Dorthe Sandvang
Keyword(s):  
Escherichia Coli ◽  
Resistance Gene ◽  
Bacterial Species ◽  
Gene Cassette ◽  
Class 1 Integron ◽  
Gram Negative ◽  
Spectinomycin Resistance ◽  
Class 1 ◽  
Genes Encoding ◽  
New Gene

ABSTRACT The aadA genes, encoding resistance to streptomycin and spectinomycin, have been found as gene cassettes in different gram-negative and gram-positive bacterial species. The present study has revealed the sequence of a new gene, aadA5, integrated as a gene cassette together with the trimethoprim resistance genedfr7 in a class 1 integron. The integron was located on a plasmid and was identified in a pathogenic porcineEscherichia coli isolate.

Functional and Structural Characterization of Acquired Pan-Aminoglycoside Resistance 16S rRNA Methyltransferase NpmB1

2021 ◽  
Author(s):  
Akito Kawai ◽  
Masahiro Suzuki ◽  
Kentaro Tsukamoto ◽  
Yusuke Minato ◽  
Yohei Doi
Keyword(s):  
Amino Acid ◽  
16S Rrna ◽  
Amino Acid Identity ◽  
Single Amino Acid ◽  
Aminoglycoside Resistance ◽  
E Coli ◽  
The United Kingdom ◽  
Amino Acid Variant ◽  
A Site

Post-translational methylation of the A site of 16S rRNA at position A1408 leads to pan-aminoglycoside resistance encompassing both 4,5- and 4,6-disubstituted 2-deoxystreptamine (DOS) aminoglycosides. To date, NpmA is the only acquired enzyme with such function. Here, we present function and structure of NpmB1 whose sequence was identified in Escherichia coli genomes registered from the United Kingdom. NpmB1 possesses 40% amino acid identity with NpmA1 and confers resistance to all clinically relevant aminoglycosides including 4,5-DOS agents. Phylogenetic analysis of NpmB1 and NpmB2, its single amino acid variant, revealed that the encoding gene was likely acquired by E. coli from a soil bacterium. The structure of NpmB1 suggests that it requires a structural change of the β6/7 linker in order to bind to 16S rRNA. These findings establish NpmB1 and NpmB2 as the second group of acquired pan-aminoglycoside resistance 16S rRNA methyltransferases.

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