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 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 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 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 Identification and Characterization of Class 1 Integron Resistance Gene Cassettes among Salmonella Strains Isolated from Imported Seafood

2008 ◽  
Vol 75 (4) ◽  
pp. 1192-1196 ◽  
Author(s):  
Ashraf A. Khan ◽  
Elizabeth Ponce ◽  
M. S. Nawaz ◽  
Chorng-Ming Cheng ◽  
Junaid A. Khan ◽  
...  
Keyword(s):  
Salmonella Enterica ◽  
Southern Hybridization ◽  
Multidrug Resistant ◽  
The Philippines ◽  
Streptomycin Resistance ◽  
Class 1 Integron ◽  
Class 1 ◽  
Identification And Characterization ◽  
Multiple Antibiotics

ABSTRACT A total of 210 Salmonella isolates, representing 64 different serovars, were isolated from imported seafood samples, and 55/210 isolates were found to be resistant to at least one antibiotic. Class 1 integrons from three multidrug-resistant Salmonella enterica strains (Salmonella enterica serovars Newport [strain 62], Typhimurium var. Copenhagen [strain 629], and Lansing [strain 803], originating from Hong Kong, the Philippines, and Taiwan, respectively) were characterized. Southern hybridization of plasmids isolated from these strains, using a class 1 integron probe, showed that trimethoprim-sulfamethoxazole and streptomycin resistance genes were located on a megaplasmid in strain 629. Our study indicates that imported seafood could be a reservoir for Salmonella isolates resistant to multiple antibiotics.

scholarly journals Dissemination of Sulfonamide Resistance Genes (sul1, sul2, and sul3) in Portuguese Salmonella enterica Strains and Relation with Integrons

2005 ◽  
Vol 49 (2) ◽  
pp. 836-839 ◽  
Author(s):  
Patrícia Antunes ◽  
Jorge Machado ◽  
João Carlos Sousa ◽  
Luísa Peixe
Keyword(s):  
Resistance Genes ◽  
Salmonella Enterica ◽  
Class 1 Integron ◽  
Gene Cassettes ◽  
Class 1 Integrons ◽  
Sulfonamide Resistance ◽  
Class 1 ◽  
Sulfonamide Resistance Genes ◽  
Different Sources

ABSTRACT In 200 sulfonamide-resistant Portuguese Salmonella isolates, 152 sul1, 74 sul2, and 14 sul3 genes were detected. Class 1 integrons were always associated with sul genes, including sul3 alone in some isolates. The sul3 gene has been identified in isolates from different sources and serotypes, which also carried a class 1 integron with aadA and dfrA gene cassettes.

scholarly journals Identification and Molecular Characterization of Class 1 Integrons in Multiresistant Escherichia coli Isolates from Poultry Litter

2012 ◽  
Vol 78 (15) ◽  
pp. 5444-5447 ◽  
Author(s):  
Elizabeth Ponce-Rivas ◽  
María-Enriqueta Muñoz-Márquez ◽  
Ashraf A. Khan
Keyword(s):  
Escherichia Coli ◽  
Poultry Litter ◽  
Class 1 Integron ◽  
Content Type ◽  
Gene Cassettes ◽  
E Coli ◽  
Class 1 ◽  
Chicken Litter ◽  
Diverse Origin

ABSTRACTThis study describes the prevalence of arrays of class 1 integron cassettes and Qnr determinants (A, B, and S) in 19 fluoroquinolone-resistantEscherichia coliisolates from chicken litter.qnrSandqnrAwere the predominant genes in these fluoroquinolone-resistant isolates, and an uncommon array ofaacA4-catB3-dfrA1gene cassettes from a class1 integron was found. Additionally,aadA1anddfrA1gene cassettes, encoding resistance to streptomycin and trimethoprim, constituted the most common genes identified and was located on megaplasmids as well on the chromosome. Antibiotic resistance, pulsed-field gel electrophoresis (PFGE), and plasmid data suggest a genetically diverse origin of poultryE. coliisolates.

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