scholarly journals Characterization of the variable region in the class 1 integron of antimicrobial-resistant Escherichia coli isolated from surface water

2016 ◽  
Vol 47 (2) ◽  
pp. 337-344 ◽  
Author(s):  
Natália Canal ◽  
Karine Lena Meneghetti ◽  
Clara Ponzi de Almeida ◽  
Marina da Rosa Bastos ◽  
Letícia Muner Otton ◽  
...  
2001 ◽  
Vol 183 (1) ◽  
pp. 235-249 ◽  
Author(s):  
Thierry Naas ◽  
Yuzuru Mikami ◽  
Tamae Imai ◽  
Laurent Poirel ◽  
Patrice Nordmann

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.


2012 ◽  
Vol 78 (15) ◽  
pp. 5444-5447 ◽  
Author(s):  
Elizabeth Ponce-Rivas ◽  
María-Enriqueta Muñoz-Márquez ◽  
Ashraf A. Khan

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.


2005 ◽  
Vol 55 (3) ◽  
pp. 367-370 ◽  
Author(s):  
Yvonne Abbott ◽  
Rebecca O'Mahony ◽  
Nola Leonard ◽  
P. Joseph Quinn ◽  
Tanny van der Reijden ◽  
...  

2018 ◽  
Vol 6 (4) ◽  
pp. 99 ◽  
Author(s):  
Rocío Colello ◽  
Alejandra Krüger ◽  
José Conza ◽  
John Rossen ◽  
Alexander Friedrich ◽  
...  

The aim of this study was to investigate the presence of class 1 integrons in a collection of Shiga toxin-producing Escherichia coli (STEC) from different origins and to characterize pheno- and genotypically the antimicrobial resistance associated to them. A collection of 649 isolates were screened for the class 1 integrase gene (intI1) by Polymerase chain reaction The variable region of class 1 integrons was amplified and sequenced. Positive strains were evaluated for the presence of antimicrobial resistance genes with microarray and for antimicrobial susceptibility by the disk diffusion method. Seven out of 649 STEC strains some to serogroups, O26, O103 and O130 isolated from cattle, chicken burger, farm environment and pigs were identified as positive for intl1. Different arrangements of gene cassettes were detected in the variable region of class 1 integron: dfrA16, aadA23 and dfrA1-aadA1. In almost all strains, phenotypic resistance to streptomycin, tetracycline, trimethoprim/sulfamethoxazole, and sulfisoxazole was observed. Microarray analyses showed that most of the isolates carried four or more antimicrobial resistance markers and STEC strains were categorized as Multridrug-resistant. Although antimicrobials are not usually used in the treatment of STEC infections, the presence of Multridrug-resistant in isolates collected from farm and food represents a risk for animal and human health.


2020 ◽  
Vol 28 (3) ◽  
pp. 331-340
Author(s):  
Mihaela Oprea ◽  
Madalina Cornelia Militaru ◽  
Adriana Simona Ciontea ◽  
Daniela Cristea ◽  
Violeta Cristea ◽  
...  

AbstractBecause little is known about the integrons which constitute an important means of spreading resistance in bacteria circulating in Romania, this study aimed to detect antibiotic resistance gene cassettes embedded in integrons in a convenient collection of 60 ciprofloxacin-resistant Escherichia coli isolates of various phylogroups, associated with community-acquired urinary tract infections. Characterization of the integrons was accomplished by PCR, restriction fragment length polymorphism typing, and DNA sequencing of each identified type. More than half of the tested E. coli strains were positive for integrons of class 1 (31 strains) or 2 (1 strain). These strains derived more frequently from phylogenetic groups A (15 of 21 strains), B1 (10 of 14 strains), and F (3 of 4 strains), respectively. While 20 strains carried class 1 integrons which could be assigned to nine types, eleven strains carried integrons that lacked the 3’-end conserved segment. The attempts made to characterize the gene cassettes located within the variable region of the various integrons identified in this study revealed the presence of genes encoding resistance to trimethoprim, aminoglycosides, beta-lactams or chloramphenicol. The evidence of transferable resistance determinants already established in the autochthonous E. coli strains highlights the need for improved control of resistance-carrying bacteria.


2005 ◽  
Vol 54 (3) ◽  
pp. 273-278 ◽  
Author(s):  
Ashraf M Ahmed ◽  
Shin-ichi Miyoshi ◽  
Sumio Shinoda ◽  
Tadashi Shimamoto

Enteroinvasive Escherichia coli (EIEC) O164 strain RIMD05091045 was isolated from a travelling patient suffering from diarrhoea at the Osaka airport quarantine facility in Japan. The strain showed multidrug resistance against streptomycin, spectinomycin, co-trimoxazole (trimethoprim/sulfamethoxazole) and ampicillin, and reduced susceptibility to ciprofloxacin. Molecular characterization of the multidrug-resistance phenotype revealed the presence of a class 1 integron containing three genes, a dihydrofolate reductase type XII gene, dfrXII, which confers resistance to trimethoprim, an aminoglycoside adenyltransferase gene, aadA2, which confers resistance to streptomycin and spectinomycin, and an ORF of unknown function. Southern blot hybridization and conjugation experiments showed that the class 1 integron was located on a transferable plasmid that was less than 90 kb in size. The resistance of EIEC O164 to ampicillin was found to be due to the presence of TEM-1 β-lactamase. On the other hand, a single mutation that has not previously been described, P158-to-S, was detected downstream of the quinolone-resistance-determining region of parC of topoisomerase IV and may be responsible for the reduced susceptibility to ciprofloxacin in this strain.


2008 ◽  
Vol 52 (10) ◽  
pp. 3589-3596 ◽  
Author(s):  
Carlos Juan ◽  
Alejandro Beceiro ◽  
Olivia Gutiérrez ◽  
Sebastián Albertí ◽  
Margalida Garau ◽  
...  

ABSTRACT During a survey conducted to evaluate the incidence of class B carbapenemase (metallo-β-lactamase [MBL])-producing Pseudomonas aeruginosa strains from hospitals in Majorca, Spain, five clinical isolates showed a positive Etest MBL screening test result. In one of them, strain PA-SL2, the presence of a new bla VIM derivative (bla VIM-13) was detected by PCR amplification with bla VIM-1-specific primers followed by sequencing. The bla VIM-13-producing isolate showed resistance to all β-lactams (except aztreonam), gentamicin, tobramycin, and ciprofloxacin. VIM-13 exhibited 93% and 88% amino acid sequence identities with VIM-1 and VIM-2, respectively. bla VIM-13 was cloned in parallel with bla VIM-1, and the resistance profile conferred was analyzed both in Escherichia coli and in P. aeruginosa backgrounds. Compared to VIM-1, VIM-13 conferred slightly higher levels of resistance to piperacillin and lower levels of resistance to ceftazidime and cefepime. VIM-13 and VIM-1 were purified in parallel as well, and their kinetic parameters were compared. The k cat/K m ratios for the antibiotics mentioned above were in good agreement with the MIC data. Furthermore, EDTA inhibited the activity of VIM-13 approximately 25 times less than it inhibited the activity of VIM-1. VIM-13 was harbored in a class 1 integron, along with a new variant (Ala108Thr) of the aminoglycoside-modifying enzyme encoding gene aacA4, which confers resistance to gentamicin and tobramycin. Finally, the VIM-13 integron was apparently located in the chromosome, since transformation and conjugation experiments consistently yielded negative results and the bla VIM-13 probe hybridized only with the genomic DNA.


1999 ◽  
Vol 43 (12) ◽  
pp. 2925-2929 ◽  
Author(s):  
Lydia Bass ◽  
Cynthia A. Liebert ◽  
Margie D. Lee ◽  
Anne O. Summers ◽  
David G. White ◽  
...  

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.


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