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 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.

scholarly journals Epidemiology of Rifampin ADP-Ribosyltransferase (arr-2) and Metallo-β-Lactamase (blaIMP-4) Gene Cassettes in Class 1 Integrons in Acinetobacter Strains Isolated from Blood Cultures in 1997 to 2000

2003 ◽  
Vol 47 (4) ◽  
pp. 1382-1390 ◽  
Author(s):  
Elizabeth T. S. Houang ◽  
Yiu-Wai Chu ◽  
Wai-Sing Lo ◽  
Ka-Yi Chu ◽  
Augustine F. B. Cheng
Keyword(s):  
Genomic Dna ◽  
Gene Cassette ◽  
Blood Cultures ◽  
Gene Cassettes ◽  
Class 1 Integrons ◽  
Class 1 ◽  
New Gene ◽  
Group 3 ◽  
Group 2 ◽  
Adp Ribosyltransferase

ABSTRACT We characterized two new gene cassettes in an Acinetobacter isolate: one harbored the metallo-β-lactamase (IMP-4) gene bla IMP-4, the other harbored the rifampin ADP-ribosyltransferase (ARR-2) gene arr-2, and both arrayed with the aminoglycoside acetyltransferase [AAC(6′)-Ib7] gene cassette aacA4 in two separate class 1 integrons. The epidemiology of these gene cassettes in isolates from blood cultures obtained from 1997 to 2000 was studied. Isolates bearing either the bla IMP-4 or the arr-2 gene cassette or both represented 17.5% (10 of 57) of isolates in 1997, 16.1% (10 of 62) in 1998, 2.5% (1 of 40) in 1999, and 0% (0 of 58) in 2000. These two gene cassettes, probably borne on two separate integrons, were found in at least three genomic DNA groups, with evidence of clonal dissemination in the intensive care unit during 1997 to 1998. Seventeen of the 52 Acinetobacter baumannii (genomic DNA group 2) isolates from 1997 to 2000 harbored intI1, but only one was positive for these gene cassettes, whereas 20 of the 21 intI1-positive isolates of all other genomic DNA groups were positive for either or both of them. Reduced susceptibility to imipenem and rifampin was seen only in isolates harboring the bla IMP-4 and arr-2 cassettes, respectively. The aminoglycoside phosphotransferase [APH(3′)-VIa] gene aph(3′)-VIa was detected in all 21 isolates for which the MIC of amikacin was ≥8 μg/ml, with or without aacA4, whereas aacA4 alone was found in isolates for which the MIC of amikacin was 0.5 to 2 μg/ml. Significant differences between the 17 intI1-positive and 47 intI1-negative isolates belonging to genomic DNA group 3 from 1997 to 1998 in the MICs of amikacin, gentamicin, imipenem, sulfamethoxazole, and ceftazidime were observed (Mann-Whitney test, P < 0.001 to 0.01).

scholarly journals Diversity of Gene Cassette Promoters in Class 1 Integrons from Wastewater Environments

2012 ◽  
Vol 78 (15) ◽  
pp. 5413-5416 ◽  
Author(s):  
Alexandra Moura ◽  
Thomas Jové ◽  
Marie-Cécile Ploy ◽  
Isabel Henriques ◽  
António Correia
Keyword(s):  
Gene Cassette ◽  
High Expression ◽  
Gene Cassettes ◽  
Class 1 Integrons ◽  
Class 1 ◽  
Clinical Environments

ABSTRACTThe diversity of gene cassette promoters in class 1 integrons was investigated in 47 strains isolated from wastewaters. The weak PcW and PcH1 variants predominated, suggesting that, similar to clinical environments, high rates of gene cassette recombination, rather than high expression of gene cassettes, have been preferentially selected in wastewaters.

scholarly journals Prevalence and Genetic Analysis of Plasmid-Mediated Quinolone Resistance Determinants QnrA and QnrS in Enterobacteriaceae Isolates from a French University Hospital

2006 ◽  
Vol 50 (12) ◽  
pp. 3992-3997 ◽  
Author(s):  
Laurent Poirel ◽  
Cécile Leviandier ◽  
Patrice Nordmann
Keyword(s):  
Genetic Analysis ◽  
Nalidixic Acid ◽  
Insertion Sequence ◽  
Quinolone Resistance ◽  
University Hospital ◽  
Class 1 Integrons ◽  
Resistance Determinants ◽  
Class 1 ◽  
Resistant Strains ◽  
Lactamase Gene

ABSTRACT The spread of plasmid-mediated quinolone resistance determinants QnrA and QnrS was evaluated in a collection of 186 extended-spectrum β-lactamase (ESBL)-positive enterobacterial isolates from 2002 to 2005 and 185 nalidixic acid-resistant strains isolated during the first 6 months of 2005 at the Bicêtre hospital, France. Out of these 186 ESBL-positive isolates, 2.2 and 1.6% carried a QnrA1 and a QnrS1 determinant, respectively. The ESBLs associated with QnrA1 were VEB-1, SHV-12, and CTX-M-1, whereas those associated with QnrS1 were TEM-52, SHV-12, and CTX-M-1. Among the 185 nalidixic acid-resistant strains isolated in 2005, 0.5 and 2.7% had a QnrA1 determinant and a QnrS1 determinant, respectively. The genetic environments of the qnrA1 gene differed but were always associated with sul1 type integrons. In contrast, qnrS1 genes were not embedded in class 1 integrons but located often (but not systematically) downstream of the insertion sequence ISEcl2 on plasmids that often carried a novel β-lactamase gene, bla LAP-1. This is the first study identifying the QnrS resistance determinant in Europe and indicating that this determinant might also be widespread.

scholarly journals Distribution and Content of Class 1 Integrons in Different Vibrio cholerae O-Serotype Strains Isolated in Thailand

2000 ◽  
Vol 44 (5) ◽  
pp. 1315-1321 ◽  
Author(s):  
Anders Dalsgaard ◽  
Anita Forslund ◽  
Oralak Serichantalergs ◽  
Dorthe Sandvang
Keyword(s):  
Antibiotic Resistance ◽  
Vibrio Cholerae ◽  
Resistance Gene ◽  
Resistance Genes ◽  
Antibiotic Resistance Gene ◽  
Antibiotic Resistance Genes ◽  
Gene Cassette ◽  
Gene Cassettes ◽  
Class 1 Integrons ◽  
Class 1

ABSTRACT In this study, 176 clinical and environmental Vibrio cholerae strains of different O serotypes isolated in Thailand from 1982 to 1995 were selected and studied for the presence of class 1 integrons, a new group of genetic elements which carry antibiotic resistance genes. Using PCR and DNA sequencing, we found that 44 isolates contained class 1 integrons harboring the aadB,aadA2, blaP1, dfrA1, anddfrA15 gene cassettes, which encode resistance to gentamicin, kanamycin, and tobramycin; streptomycin and spectinomycin; β-lactams; and trimethoprim, respectively. Each cassette array contained only a single antibiotic resistance gene. Although resistance genes in class 1 integrons were found in strains from the same epidemic, as well as in unrelated non-O1, non-O139 strains isolated from children with diarrhea, they were found to encode only some of the antibiotic resistance expressed by the strains. Serotype O139 strains did not contain class 1 integrons. However, the appearance and disappearance of the O139 serotype in the coastal city Samutsakorn in 1992 and 1993 were associated with the emergence of a distinct V. cholerae O1 strain which contained the aadA2resistance gene cassette. A 150-kb self-transmissible plasmid found in three O1 strains isolated in 1982 contained the aadB gene cassette. Surprisingly, several strains harbored two integrons containing different cassettes. Thus, class 1 integrons containing various resistance gene cassettes are distributed among differentV. cholerae O serotypes of mainly clinical origin in Thailand.

Antimicrobial resistance patterns and characterization of integrons in clinical isolates of Shigella from China

2014 ◽  
Vol 60 (4) ◽  
pp. 237-242 ◽  
Author(s):  
Haifei Yang ◽  
Yachao Pan ◽  
Lifen Hu ◽  
Yanyan Liu ◽  
Ying Ye ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Antimicrobial Agents ◽  
Wide Distribution ◽  
Class 1 Integron ◽  
Gene Cassettes ◽  
Class 1 Integrons ◽  
Class 1 ◽  
Shigella Spp ◽  
Resistance Patterns ◽  
Resistance Rates

One hundred fifty-three Shigella isolates were examined for multiple antibiotic resistance phenotypes and prevalence of class 1 and class 2 integron sequences. The gene cassettes dfrA17-aadA5, dfrA12-orfF-aadA2, and arr-3-aacA4 were found in typical class 1 integrons. The gene cassettes blaOXA-1-aadA1 and dfrA1-sat1-aadA1 were detected in atypical class 1 integrons and in class 2 integrons, respectively. This is the first report of arr-3-aacA4 cassette detected in typical class 1 integrons among Shigella isolates. Rates of antibiotic resistance were different between integron-positive and integron-negative strains (P < 0.05), and all integron-positive isolates were resistant to at least 3 different antimicrobial agents. Typical class 1 integron-positive isolates showed higher resistance rates to cefotaxime and ciprofloxacin than did integron-negative ones (P < 0.05). Typical class 1 integrons and β-lactamase genes were found in conjugative plasmids, otherwise class 2 and atypical class 1 integrons were located on chromosome. This study demonstrated the wide distribution of class 1 integrons in Shigella spp., which may lead resistance to cefotaxime and ciprofloxacin in China.

Antibiotic selective pressure for the maintenance of antibiotic resistant genes in coliform bacteria isolated from the aquatic environment

2003 ◽  
Vol 47 (3) ◽  
pp. 249-253 ◽  
Author(s):  
J.C. Park ◽  
J.C. Lee ◽  
J.Y. Oh ◽  
Y.W. Jeong ◽  
J.W. Cho ◽  
...  
Keyword(s):  
Aquatic Environment ◽  
Selective Pressure ◽  
Functional Class ◽  
Coliform Bacteria ◽  
Antibiotic Resistant ◽  
Gene Cassettes ◽  
Class 1 Integrons ◽  
Selective Pressures ◽  
Class 1 ◽  
Inti1 Gene

Coliform bacteria isolated from the aquatic environment were investigated for antibiotic susceptibility and detailed structures of class 1 integrons. A high proportion of isolates were found to be resistant to sulfamethoxazole, aminoglycosides, and β-lactams. The 750 (53.6%) isolates were resistant to one or more of the antibiotics tested out of 1,400 coliform bacteria. Based on the MIC of antibiotics and antibiogram, 150 isolates were selected and further studied for class 1 integrons. The intI1 gene was found in 36 (24.0%) of the 150 isolates. Twelve isolates carried the gene cassettes responsible for antibiotic resistance, while no gene cassettes were found in 24 isolates. Seven different genes, dfrA5, dfrA7, dfrA12, dfrA17, aaA2, aaA5, and aad(3’), were detected in gene cassettes. The dfrA and aad genes located on class 1 integrons were responsible for resistance to trimethoprim and aminoglycosides. The remaining 24 coliform bacteria had the incomplete or non-functional class 1 integrons. These results indicated that antibiotic selective pressures may play an important role to maintain gene cassettes of class 1 integrons and in the absence of sustained antibiotic pressures, such as the aquatic environment, coliform bacteria may carry empty or non-functional class 1 integrons.

scholarly journals Molecular Basis of Sulfonamide and Trimethoprim Resistance in Fish-Pathogenic Aeromonas Isolates

2011 ◽  
Vol 77 (20) ◽  
pp. 7147-7150 ◽  
Author(s):  
Kristina Kadlec ◽  
Ellen von Czapiewski ◽  
Heike Kaspar ◽  
Jürgen Wallmann ◽  
Geovana Brenner Michael ◽  
...  
Keyword(s):  
Resistance Genes ◽  
Molecular Basis ◽  
Aeromonas Salmonicida ◽  
The Novel ◽  
Content Type ◽  
Gene Cassettes ◽  
Class 1 Integrons ◽  
Novel Gene ◽  
Class 1 ◽  
Diseased Fish

ABSTRACTSulfonamide-trimethoprim-resistantAeromonas salmonicidaand motileAeromonasspp. from diseased fish of the GERM-Vet study carried thesul1gene together with mostly cassette-borne trimethoprim resistance genes, including the novel genedfrA28. The sevendfrAanddfrBgenes identified were located mostly in class 1 integrons which commonly harbored other gene cassettes.

Antimicrobial Resistance, Extended-Spectrum β-Lactamase Productivity, and Class 1 Integrons in Escherichia coli from Healthy Swine

2015 ◽  
Vol 78 (8) ◽  
pp. 1442-1450 ◽  
Author(s):  
KANJANA CHANGKAEW ◽  
APIRADEE INTARAPUK ◽  
FUANGFA UTRARACHKIJ ◽  
CHIE NAKAJIMA ◽  
ORASA SUTHIENKUL ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Antimicrobial Resistance ◽  
Intestinal Flora ◽  
Class 1 Integron ◽  
Potential Health ◽  
Gene Cassettes ◽  
E Coli ◽  
Class 1 Integrons ◽  
Extended Spectrum ◽  
Class 1

Administration of antimicrobials to food-producing animals increases the risk of higher antimicrobial resistance in the normal intestinal flora of these animals. The present cross-sectional study was conducted to investigate antimicrobial susceptibility and extended-spectrum β-lactamase (ESBL)–producing strains and to characterize class 1 integrons in Escherichia coli in healthy swine in Thailand. All 122 of the tested isolates had drug-resistant phenotypes. High resistance was found to ampicillin (98.4% of isolates), chloramphenicol (95.9%), gentamicin (78.7%), streptomycin (77.9%), tetracycline (74.6%), and cefotaxime (72.1%). Fifty-four (44.3%) of the E. coli isolates were confirmed as ESBL-producing strains. Among them, blaCTX-M (45 isolates) and blaTEM (41 isolates) were detected. Of the blaCTX-M-positive E. coli isolates, 37 carried the blaCTX-M-1 cluster, 12 carried the blaCTX-M-9 cluster, and 5 carried both clusters. Sequence analysis revealed blaTEM-1, blaTEM-135, and blaTEM-175 in 38, 2, and 1 isolate, respectively. Eighty-seven (71%) of the 122isolates carried class 1 integrons, and eight distinct drug-resistance gene cassettes with seven different integron profiles were identified in 43 of these isolates. Gene cassettes were associated with resistance to aminoglycosides (aadA1, aadA2, aadA22, or aadA23), trimethoprim (dfrA5, dfrA12, or dfrA17), and lincosamide (linF). Genes encoding β-lactamases were not found in class 1 integrons. This study is the first to report ESBL-producing E. coli with a class 1 integron carrying the linF gene cassette in swine in Thailand. Our findings confirm that swine can be a reservoir of ESBL-producing E. coli harboring class 1 integrons, which may become a potential health risk if these integrons are transmitted to humans. Intensive analyses of animal, human, and environmental isolates are needed to control the spread of ESBL-producing E. coli strains.

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