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 Incidence and Characterization of Integrons, Genetic Elements Mediating Multiple-Drug Resistance, in AvianEscherichia coli

1999 ◽  
Vol 43 (12) ◽  
pp. 2925-2929 ◽  
Author(s):  
Lydia Bass ◽  
Cynthia A. Liebert ◽  
Margie D. Lee ◽  
Anne O. Summers ◽  
David G. White ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Resistance Gene ◽  
Multiple Drug Resistance ◽  
Marker Gene ◽  
Clinical Isolates ◽  
Multiple Antibiotic Resistance ◽  
Class 1 Integron ◽  
E Coli ◽  
Class 1

ABSTRACT Antibiotic resistance among avian bacterial isolates is common and is of great concern to the poultry industry. Approximately 36% (n = 100) of avian, pathogenic Escherichia coli isolates obtained from diseased poultry exhibited multiple-antibiotic resistance to tetracycline, oxytetracycline, streptomycin, sulfonamides, and gentamicin. Clinical avian E. coli isolates were further screened for the presence of markers for class 1 integrons, the integron recombinase intI1 and the quaternary ammonium resistance gene qacEΔ1, in order to determine the contribution of integrons to the observed multiple-antibiotic resistance phenotypes. Sixty-three percent of the clinical isolates were positive for the class 1 integron markersintI1 and qacEΔ1. PCR analysis with the conserved class 1 integron primers yielded amplicons of approximately 1 kb from E. coli isolates positive for intI1 andqacEΔ1. These PCR amplicons contained the spectinomycin-streptomycin resistance gene aadA1. Further characterization of the identified integrons revealed that many were part of the transposon Tn21, a genetic element that encodes both antibiotic resistance and heavy-metal resistance to mercuric compounds. Fifty percent of the clinical isolates positive for the integron marker gene intI1 as well as for theqacEΔ1 and aadA1 cassettes also contained the mercury reductase gene merA. The correlation between the presence of the merA gene with that of the integrase and antibiotic resistance genes suggests that these integrons are located in Tn21. The presence of these elements among avianE. coli isolates of diverse genetic makeup as well as inSalmonella suggests the mobility of Tn21 among pathogens in humans as well as poultry.

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 In53, a Class 1 Plasmid- and Composite Transposon-Located Integron of Escherichia coli Which Carries an Unusual Array of Gene Cassettes

2001 ◽  
Vol 183 (1) ◽  
pp. 235-249 ◽  
Author(s):  
Thierry Naas ◽  
Yuzuru Mikami ◽  
Tamae Imai ◽  
Laurent Poirel ◽  
Patrice Nordmann
Keyword(s):  
Escherichia Coli ◽  
Resistance Gene ◽  
Gene Cassette ◽  
Promoter Sequence ◽  
Class 1 Integron ◽  
Integrase Gene ◽  
Chloramphenicol Resistance ◽  
Gene Cassettes ◽  
Class 1

ABSTRACT Further characterization of the genetic environment of the gene encoding the Escherichia coli extended-spectrum β-lactamase, bla VEB-1, revealed the presence of a plasmid-located class 1 integron, In53, which carried eight functional resistance gene cassettes in addition tobla VEB-1. While the aadB and the arr-2 gene cassettes were identical to those previously described, the remaining cassettes were novel: (i) a novel nonenzymatic chloramphenicol resistance gene of the cmlAfamily, (ii) a qac allele encoding a member of the small multidrug resistance family of proteins, (iii) a cassette,aacA1b/orfG, which encodes a novel 6′-N-acetyltransferase, and (iv) a fused gene cassette,oxa10/aadA1, which is made of two cassettes previously described as single cassettes. In addition, oxa10 andaadA1 genes were expressed from their own promoter sequence present upstream of the oxa10 cassette.arr-2 coded for a protein that shared 54% amino acid identity with the rifampin ADP-ribosylating transferase encoded by thearr-1 gene from Mycobacterium smegmatisDSM43756. While in M. smegmatis, the main inactivated compound was 23-ribosyl-rifampin, the inactivated antibiotic recovered from E. coli culture was 23-O-ADP-ribosyl-rifampin. The integrase gene of In53 was interrupted by an IS26 insertion sequence, which was also present in the 3′ conserved segment. Thus, In53 is a truncated integron located on a composite transposon, named Tn2000, bounded by two IS26 elements in opposite orientations. Target site duplication at both ends of the transposon indicated that the integron likely was inserted into the plasmid through a transpositional process. This is the first description of an integron located on a composite transposon.

scholarly journals Characterization of class 1 integron resistance gene cassettes in Salmonella enterica serovars Oslo and Bareily from imported seafood

2006 ◽  
Vol 58 (6) ◽  
pp. 1308-1310 ◽  
Author(s):  
A. A. Khan ◽  
C.-M. Cheng ◽  
K. T. Van ◽  
C. S. West ◽  
M. S. Nawaz ◽  
...  
Keyword(s):  
Resistance Gene ◽  
Salmonella Enterica ◽  
Class 1 Integron ◽  
Gene Cassettes ◽  
Class 1

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.

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