scholarly journals A Family of Insertion Sequences That Impacts Integrons by Specific Targeting of Gene Cassette Recombination Sites, the IS1111-attC Group

2008 ◽  
Vol 190 (14) ◽  
pp. 4959-4970 ◽  
Author(s):  
Sasha G. Tetu ◽  
Andrew J. Holmes
Keyword(s):  
Gene Cassette ◽  
Evolutionary Divergence ◽  
Insertion Sequences ◽  
Site Specific ◽  
Gene Cassettes ◽  
Genetic Elements ◽  
Complex Phenotypes ◽  
Class 1 ◽  
Linkage Of Genes ◽  
The Right

ABSTRACT Integrons facilitate the evolution of complex phenotypes by physical and transcriptional linkage of genes. They can be categorized as chromosomal integrons (CIs) or mobile resistance integrons (MRIs). The significance of MRIs for the problem of multiple antibiotic resistance is well established. CIs are more widespread, but their only demonstrated significance is as a reservoir of gene cassettes for MRIs. In characterizing CIs associated with Pseudomonas, we discovered a subfamily of insertion sequences, termed the IS1111-attC group, that insert into the recombination sites of gene cassettes (attC site) by site-specific recombination. IS1111-attC elements appear to have recently spread from Pseudomonas species to clinical class 1 integrons. Such elements are expected to significantly impact integrons. To explore this further, we examined CIs in 24 strains representing multiple levels of evolutionary divergence within the genus Pseudomonas. Cassette arrays frequently had a degenerated “footprint” of an IS1111-attC group element at their terminus and in three cases were occupied by multiple functional IS1111-attC elements. Within Pseudomonas spp. the IS-integron interaction appears to follow an evolutionarily rapid cycle of infection, expansion, and extinction. The final outcome is extinction of the IS element and modification of the right-hand boundary of the integron. This system represents an unusual example of convergent evolution whereby heterologous families of site-specific recombinases of distinct genetic elements have adopted the same target site. The interactions described here represent a model for evolutionary processes that offer insights to a number of aspects of the biology of integrons and other mosaic genetic elements.

scholarly journals Characterization of the Metallo-β-Lactamase Determinant of Acinetobacter baumannii AC-54/97 Reveals the Existence of blaIMP Allelic Variants Carried by Gene Cassettes of Different Phylogeny

2000 ◽  
Vol 44 (5) ◽  
pp. 1229-1235 ◽  
Author(s):  
Maria Letizia Riccio ◽  
Nicola Franceschini ◽  
Letizia Boschi ◽  
Berardo Caravelli ◽  
Giuseppe Cornaglia ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Acinetobacter Baumannii ◽  
Kinetic Parameters ◽  
Gene Cassette ◽  
Global Risk ◽  
Allelic Variants ◽  
Gene Cassettes ◽  
Class 1 ◽  
Broad Array ◽  
Environmental Reservoir

ABSTRACT The metallo-β-lactamase determinant of Acinetobacter baumannii AC-54/97, a clinical isolate from Italy that was previously shown to produce an enzyme related to IMP-1, was isolated by means of a PCR methodology which targets amplification of gene cassette arrays inserted into class 1 integrons. Sequencing revealed that this determinant was an allelic variant (namedbla IMP-2) of bla IMPfound in Japanese isolates and that it was divergent from the latter by 12% of its nucleotide sequence, which evidently had been acquired independently. Similar to bla IMP,bla IMP-2 was also carried by an integron-borne gene cassette. However, the 59-base element of thebla IMP-2 cassette was unrelated to those of thebla IMP cassettes found in Japanese isolates, indicating a different phylogeny for the gene cassettes carrying the two allelic variants. Expression of the integron-bornebla IMP-2 gene in Escherichia coliresulted in a significant decrease in susceptibility to a broad array of β-lactams (ampicillin, carbenicillin, cephalothin, cefoxitin, ceftazidime, cefepime, and carbapenems). The IMP-2 enzyme was purified from an Escherichia coli strain carrying the cloned determinant, and kinetic parameters were determined with several β-lactam substrates. Compared to IMP-1, the kinetic parameters of IMP-2 were similar overall with some β-lactam substrates (cefoxitin, ceftazidime, cefepime, and imipenem) but remarkably different with others (ampicillin, carbenicillin, cephaloridine, and meropenem), revealing a functional significance of at least some of the mutations that differentiate the two IMP variants. Present findings suggest that the environmental reservoir of bla IMP alleles could be widespread and raise a question about the global risk of their transfer to clinically relevant species.

scholarly journals Molecular Characterization of a New Class 3 Integron in Klebsiella pneumoniae

2003 ◽  
Vol 47 (9) ◽  
pp. 2838-2843 ◽  
Author(s):  
Mário Correia ◽  
Filipa Boavida ◽  
Filipa Grosso ◽  
M. J. Salgado ◽  
L. M. Lito ◽  
...  
Keyword(s):  
Klebsiella Pneumoniae ◽  
Gene Cassette ◽  
Promoter Regions ◽  
Fusion Event ◽  
Integrase Gene ◽  
Gene Cassettes ◽  
New Class ◽  
Extended Spectrum ◽  
Class 1 ◽  
Cephalosporin Resistance

ABSTRACT Klebsiella pneumoniae FFUL 22K was isolated in April 1999 from the urine of an intensive care unit patient in Portugal. The strain showed an extended-spectrum cephalosporin resistance profile. A typical synergistic effect between cefotaxime or cefepime and clavulanic acid was observed. An Escherichia coli transformant displayed a similar resistance phenotype and harbored a ca. 9.4-kb plasmid (p22K9). Cloning experiments revealed that the extended-spectrum β-lactamase was encoded by bla GES-1, previously described in class 1 integrons from K. pneumoniae ORI-1 and Pseudomonas aeruginosa Pa695. Further sequence analysis demonstrated that the bla GES-1 gene cassette was located on a new class 3 integron. The integron was 2,863 bp long and consisted of an intI3 integrase gene, an attI3 recombination site, two promoter regions, and two gene cassettes. The IntI3 integrase was 98.8% identical to that of Serratia marcescens AK9373. The bla GES-1 gene cassette was inserted at the attI3 site. The second gene cassette was the result of a fusion event between bla OXA-10-type and aac(6′)-Ib gene cassettes and conferred resistance to kanamycin. This is the second class 3 integron reported and the first time that the bla GES-1 gene cassette has been found on an integron belonging to this class, highlighting the considerable heterogeneity of their genetic environment and the spread of gene cassettes among different classes of integrons.

scholarly journals The aadB Gene Cassette Is Associated with blaSHV Genes in Klebsiella Species Producing Extended-Spectrum β-Lactamases

2005 ◽  
Vol 49 (2) ◽  
pp. 794-797 ◽  
Author(s):  
Louisa A. Jones ◽  
Christopher J. McIver ◽  
Mi-Jurng Kim ◽  
William D. Rawlinson ◽  
Peter A. White
Keyword(s):  
Gene Cassette ◽  
Amplicon Sequencing ◽  
Klebsiella Species ◽  
Class 1 Integron ◽  
Beta Lactamases ◽  
Gene Cassettes ◽  
Extended Spectrum ◽  
Class 1 ◽  
Extended Spectrum Beta Lactamases

ABSTRACT Integrons were detected in 37 (72.5%) of 51 Klebsiella spp. producing extended-spectrum beta-lactamases by PCR with primers that targeted integrase genes and cassette regions. PCR and amplicon sequencing of the cassette regions revealed aadB and aadA2 gene cassettes that confer resistance to a range of aminoglycosides. aadB was associated with a class 1 integron on a 28-kb plasmid, pES1, that also contained bla SHV-12 and IS26.

Identification of plasmid- and integron-borne bla IMP-1 and bla IMP-10 in clinical isolates of Serratia marcescens

2009 ◽  
Vol 58 (2) ◽  
pp. 217-221 ◽  
Author(s):  
Zhuting Hu ◽  
Wei-Hua Zhao
Keyword(s):  
Serratia Marcescens ◽  
Single Point ◽  
Gene Cassette ◽  
Clinical Isolates ◽  
Single Point Mutation ◽  
Class 1 Integron ◽  
Gene Cassettes ◽  
E Coli ◽  
Class 1 ◽  
P2 Promoter

The emergence of carbapenem-hydrolysing metallo-β-lactamases (MBLs) is a serious threat to the clinical utility of carbapenems. This study identified plasmid- and integron-borne bla IMP-1 and bla IMP-10 in clinical isolates of Serratia marcescens. The bla IMP-1 and bla IMP-10 gene cassettes were carried by a class 1 integron and followed by the aac(6′)-IIc gene cassette. The bla IMP-1 and bla IMP-10 gene cassettes were preceded by a weak Pant promoter, TGGACA(N)17TAAGCT, and an inactive P2 promoter, TTGTTA(N)14TACAGT. These genes were easily transferred to Escherichia coli by conjugation and transformation, indicating that they are located on transferable plasmids. Due to the acquisition of bla IMP-1, the susceptibility of E. coli transconjugants to imipenem, meropenem, panipenem and biapenem decreased by 32-, 256-, 64- and 128-fold, respectively. In comparison, after gaining bla IMP-10, the susceptibility of E. coli transconjugants to the four carbapenems decreased by 64-, 2048-, 256- and 64-fold, respectively. Strains harbouring bla IMP-10 showed higher-level resistance to imipenem, meropenem and panipenem than the strains harbouring bla IMP-1, although the nucleotide sequences of the class 1 integrons carrying bla IMP-10 and bla IMP-1 were identical except for a single point mutation.

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 High Genetic Stability of Integrons in Clinical Isolates of Shigella spp. of Worldwide Origin

2007 ◽  
Vol 51 (4) ◽  
pp. 1333-1340 ◽  
Author(s):  
Véronique Dubois ◽  
Marie-Pierre Parizano ◽  
Corinne Arpin ◽  
Laure Coulange ◽  
Marie-Christine Bezian ◽  
...  
Keyword(s):  
Insertion Sequence ◽  
Gene Cassette ◽  
University Hospital ◽  
Ampicillin Resistance ◽  
Gene Cassettes ◽  
Class 1 Integrons ◽  
The World ◽  
Class 1 ◽  
Shigella Spp ◽  
History Of

ABSTRACT Over a 12-year period, 68 Shigella strains (31 S. sonnei, 30 S. flexneri, 4 S. dysenteriae, and 3 S. boydii strains) were collected in a French University Hospital from the stools of patients who generally had a recent history of travel to various parts of the world (91%), particularly Africa (67%). These strains were often resistant (streptomycin, spectinomycin, trimethoprim, tetracycline, and sulfonamides, 66 to 84%; ampicillin and chloramphenicol, 34 to 38%; nalidixic acid, 4%) and even multiresistant (87%), and they generally carried integrons (81%) of class 1 (21%), class 2 (47%), or both (13%). Class 1 integrons were associated with ampicillin resistance due to the production of an OXA-30 β-lactamase in S. flexneri and S. dysenteriae. Class 2 integrons were associated with trimethoprim resistance in S. sonnei. Class 1 and class 2 integrons were inserted within transposons Tn21 and Tn7, respectively, themselves located on the bacterial chromosome, except in one strain. Class 1 integrons showed an atypical organization consisting of the insertion sequence IS1 at the 3′ end instead of the typical 3′ conserved segment and two bla OXA-30 and aadA1 gene cassettes, despite the absence of epidemiological relationships between the strains, and an apparently functional integrase. Class 2 integrons showed the same albeit classical organization with the three dfrA1, sat, and aadA1 gene cassettes. Occasionally, the 3′ end was deleted and the aadA1 gene cassette was unexpressed. Thus, integrons contributed only in part to the multidrug resistance of the Shigella strains. The highly conserved organization of integrons might be related to their location within mobile genetic superstructures.

scholarly journals Genetic Environments of Plasmid-Mediated blaCTXM-15 beta-lactamase gene in Enterobacteriaceae from Africa

2020 ◽  
Author(s):  
Babafela Awosile ◽  
Michael Agbaje
Keyword(s):  
Insertion Sequence ◽  
Gene Cassette ◽  
Global Scale ◽  
Insertion Sequences ◽  
M Gene ◽  
African Countries ◽  
Eligibility Criteria ◽  
Class 1 Integron ◽  
Genetic Environment ◽  
Class 1

The most widely distributed blaCTX-M gene on a global scale is blaCTX-M-15. The dissemination has been associated with clonal spread and different types of mobile genetic elements. This study aimed to review and describe the genetic environments of blaCTX-M-15 gene detected from Enterobacteriaceae in published literature from Africa. A literature search for relevant articles was done through PubMed, and Google Scholars electronic databases, 43 articles from 17 African countries were included in the review based on the eligibility criteria. Insertion sequences were reported as part of the genetic environment of blaCTX-M-15 gene in 32 studies, integrons in 13 studies, and plasmids in 23 studies. In this review, five insertion sequences including ISEcp1, IS26, orf447, IS903, and IS3 have been detected associated with the genetic environment of blaCTX-M-15 in Africa. Seven different genetic patterns were seen in blaCTX-M-15 genetic environment. Insertion sequence ISEcp1 was commonly located upstream of the end of the blaCTX-M-15 gene while insertion sequence orf477 was located downstream. In some studies, ISEcp1 was truncated upstream of blaCTX-M-15 by insertion sequences IS26 and IS3. Class 1 integron (Intl1) was most reported to be associated with blaCTX-M-15 (13 studies), with Intl1/dfrA17–aadA5 being the most common gene cassette array. IncFIA-FIB-FII multi-replicons and IncHI2 replicon types were the most common plasmid replicon types that horizontally transfer blaCTX-M-15 gene. Aminoglycoside modifying enzymes, and plasmid-mediated quinolone resistance genes were commonly collocated with blaCTX-M-15 gene on plasmids. This review revealed the predominant role of ISEcp1, Intl1and IncF plasmid in the mobilization and continental dissemination of the blaCTX-M-15 gene in Africa.

scholarly journals New Determinants of Aminoglycoside Resistance and Their Association with the Class 1 Integron Gene Cassettes in Trueperella pyogenes

2020 ◽  
Vol 21 (12) ◽  
pp. 4230
Author(s):  
Ewelina Kwiecień ◽  
Ilona Stefańska ◽  
Dorota Chrobak-Chmiel ◽  
Agnieszka Sałamaszyńska-Guz ◽  
Magdalena Rzewuska
Keyword(s):  
Resistance Genes ◽  
Resistance Mechanisms ◽  
Aminoglycoside Resistance ◽  
Class 1 Integron ◽  
Gene Cassettes ◽  
Genetic Elements ◽  
Trueperella Pyogenes ◽  
Broth Microdilution Method ◽  
Class 1 ◽  
Aminoglycoside Resistance Genes

Trueperella pyogenes is an important opportunistic animal pathogen. Different antimicrobials, including aminoglycosides, are used to treat T. pyogenes infections. The aim of the present study was to evaluate aminoglycoside susceptibility and to detect aminoglycoside resistance determinants in 86 T. pyogenes isolates of different origin. Minimum inhibitory concentration of gentamicin, streptomycin, and kanamycin was determined using a standard broth microdilution method. Genetic elements associated with aminoglycoside resistance were investigated by PCR and DNA sequencing. All studied isolates were susceptible to gentamicin, but 32.6% and 11.6% of them were classified as resistant to streptomycin and kanamycin, respectively. A total of 30 (34.9%) isolates contained class 1 integrons. Class 1 integron gene cassettes carrying aminoglycoside resistance genes, aadA11 and aadA9, were found in seven and two isolates, respectively. Additionally, the aadA9 gene found in six isolates was not associated with mobile genetic elements. Moreover, other, not carried by gene cassettes, aminoglycoside resistance genes, strA-strB and aph(3’)-IIIa, were also detected. Most importantly, this is the first description of all reported genes in T. pyogenes. Nevertheless, the relevance of the resistance phenotype to genotype was not perfectly matched in 14 isolates. Therefore, further investigations are needed to fully explain aminoglycoside resistance mechanisms in T. pyogenes.

scholarly journals Influence of industrial contamination on mobile genetic elements: class 1 integron abundance and gene cassette structure in aquatic bacterial communities

2008 ◽  
Vol 2 (4) ◽  
pp. 417-428 ◽  
Author(s):  
Meredith S Wright ◽  
Craig Baker-Austin ◽  
Angela H Lindell ◽  
Ramunas Stepanauskas ◽  
Hatch W Stokes ◽  
...  
Keyword(s):  
Bacterial Communities ◽  
Gene Cassette ◽  
Mobile Genetic Elements ◽  
Class 1 Integron ◽  
Industrial Contamination ◽  
Genetic Elements ◽  
Class 1

scholarly journals Class 1 Integron Containing a New Gene Cassette, aadA10, Associated with Tn1404 from R151

2002 ◽  
Vol 46 (8) ◽  
pp. 2400-2408 ◽  
Author(s):  
Sally R. Partridge ◽  
Christina M. Collis ◽  
Ruth M. Hall
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Gene Cassette ◽  
Class 1 Integron ◽  
Gene Cassettes ◽  
Base Element ◽  
Class 1 Integrons ◽  
Resistance Determinants ◽  
Class 1 ◽  
New Gene

ABSTRACT The carbenicillin, gentamicin, kanamycin, streptomycin, spectinomycin, sulfonamide, and tobramycin resistance determinants found on Pseudomonas aeruginosa plasmid R151 have previously been shown to translocate to another plasmid, R388, and it was inferred that a transposon, Tn1404, carried the resistance determinants. Sequencing of the cassette array from the plasmid known as R388::Tn1404 revealed two known gene cassettes, oxa10 and aadB, and a previously unidentified cassette determining resistance to streptomycin and spectinomycin, here designated aadA10, in the order oxa10-aadB-aadA10. These cassettes replaced the dfrB2-orfA cassette array of R388, indicating that movement of the resistance determinants from R151 to R388 resulted from recombinational exchange between two class 1 integrons rather than transposition. The AadA10 protein is most closely related to AadA6 (85% identical) and AadA7 (80% identical). The aadA10 cassette found here has only a simple site containing a 7-bp spacer derived from attI1 in place of a 59-base element and is likely to represent a derivative of the complete cassette. IntI1-mediated deletion of the aadA10 cassette was not detected, indicating that this single simple site is either inactive or only weakly active.

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