scholarly journals Family of Class 1 Integrons Related to In4 from Tn1696

2001 ◽  
Vol 45 (11) ◽  
pp. 3014-3020 ◽  
Author(s):  
Sally R. Partridge ◽  
Gavin D. Recchia ◽  
H. W. Stokes ◽  
Ruth M. Hall

ABSTRACT The class 1 integron In28, found in the multidrug resistance transposon Tn1403, was found to be located in theres site of the backbone transposon and is flanked by a 5-bp direct duplication, indicating that it reached this position by transposition. In28 has a backbone structure related to that of In4, but has lost internal sequences, including the sul1gene, due to an IS6100-mediated deletion. In28 also lacks the partial copy of IS6100 found in In4 and contains different gene cassettes, blaP1, cmlA1, andaadA1. In1, the class 1 integron found in the multidrug resistance plasmid R46, is also located in a putativeres site and belongs to the In4 group. In1 has a shorter internal deletion than In28 and has also lost one end. Additional integrons with structures related to In4 were also found in databases, and most of them had also lost either one end or internal regions or both. Tn610 belongs to this group.

2002 ◽  
Vol 46 (5) ◽  
pp. 1288-1294 ◽  
Author(s):  
Sally R. Partridge ◽  
Heidi J. Brown ◽  
Ruth M. Hall

ABSTRACT Two putative transposons, Tn2521 and Tn1405, carrying determinants for the PSE-4 β-lactamase and for resistance to streptomycin, spectinomycin, and sulfonamides were previously isolated from the chromosome of Pseudomonas aeruginosa Dalgleish. Detailed mapping and determination of the complete sequence of Tn2521 revealed that it is a class 1 integron, here renamed In33, with a backbone structure identical to that of In4 from Tn1696. In33 contains two gene cassettes, blaP1 and aadA1, replacing the aacC1-orfE-aadA2-cmlA1 cassette array in In4. Although In33 does not include any transposition genes, movement of In33 (Tn2521) targeted to a single location in the IncP-1 plasmid R18-18 has been reported previously (M. I. Sinclair and B. W. Holloway, J. Bacteriol. 151:569-579, 1982). A 5-bp duplication of the target, which lies within the res site recognized by the ParA resolvase of R18-18, was present, indicating that the mechanism of movement was transposition. Together, these data indicate that class 1 integrons that are defective in self-transposition can move under appropriate circumstances. The Tn1405 isolate studied was found to represent only the cassette array of In33, which had replaced the cassette array in the recipient plasmid R388, probably by homologous recombination.


2018 ◽  
Vol 16 (5) ◽  
pp. 319-327
Author(s):  
Atchariya YOSBOONRUANG ◽  
Anong KIDDEE ◽  
Chatsuda BOONDUANG ◽  
Phannarai PIBALPAKDEE

Escherichia coli is a serious cause of a variety of hospital-acquired infections and commonly contributes to the environment by house flies. Integrons, particularly class 1 integrons, are the genetic elements that play an important role in the horizontal transfer of antimicrobial resistance mechanism. This mechanism is commonly found in Enterobacteriaceae, especially E. coli. In this study, we aim to investigate the occurrence and antimicrobial resistance patterns of E. coli isolated from the house flies in Phayao hospital and to determine the gene expression of class 1 integrons in those isolates of E. coli. Totally, 70 isolates of E. coli were isolated from 60 house flies collected from the hospital. Fifty-seven of the isolates (81.43 %) were multidrug resistance (MDR) and highly resistant to b-lactams, tetracyclines, and sulfonamides. Of 57 isolates of MDR-E. coli, 20 isolates (35 %) were found to carry class 1 integron genes. Fifteen patterns of antimicrobial resistance occurred in the isolates of integron-positive E. coli. Most integron-positive E. coli isolates were resistant to 7 antimicrobials. Two isolates of these bacteria (10 %) were able to resist 13 out of 14 tested antimicrobials. Using PCR and sequencing analysis, an investigation showed that dfrA17-aadA5, dfrA12-aadA2 gene cassette was the most prevalent cassette (n = 10; 50 %) among the integron-positive E. coli isolates. Our results indicated that the presences of multidrug resistance and class 1 integrons were common in E. coli isolated from the houseflies in hospital. Therefore, screening for integron-positive E. coli from the hospital environment might be necessary for prevention of nosocomial infections.


2015 ◽  
Vol 78 (8) ◽  
pp. 1442-1450 ◽  
Author(s):  
KANJANA CHANGKAEW ◽  
APIRADEE INTARAPUK ◽  
FUANGFA UTRARACHKIJ ◽  
CHIE NAKAJIMA ◽  
ORASA SUTHIENKUL ◽  
...  

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.


2021 ◽  
Vol 55 (1 (254)) ◽  
pp. 58-66
Author(s):  
Magdalina K. Zakharyan

A total of 182 non-typhoid Salmonella enterica (NTS) isolates recovered from patients between 1996 and 2014 were included in the current study focused on class 1 integron detection and its association with multidrug resistance (MDR) phenotype. A high prevalence of isolates displaying MDR and penta-resistance (resistance to ampicillin, chloramphenicol, streptomycin, sulfonamide, tetracycline) phenotypes of clinical significance was revealed. Serotype-specific prevalence of antimicrobial resistance as well as class 1 integrons and inserted variable segments was detected in isolates. The results indicated the limitations of current antimicrobial therapy to control infections caused by MDR isolates of NTS, especially belonging to serotype Typhimurium.


2001 ◽  
Vol 67 (12) ◽  
pp. 5675-5682 ◽  
Author(s):  
Anja S. Schmidt ◽  
Morten S. Bruun ◽  
Inger Dalsgaard ◽  
Jens L. Larsen

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.


2000 ◽  
Vol 44 (10) ◽  
pp. 2684-2688 ◽  
Author(s):  
Marie-Cécile Ploy ◽  
François Denis ◽  
Patrice Courvalin ◽  
Thierry Lambert

ABSTRACT Twenty Acinetobacter baumannii strains resistant to various antibiotics were analyzed for integron content and sequences of the amplification products. Sixteen clinical isolates had a class 1 integron, 2 contained an additional class 1 or class 2 integron, but no class 3 integron was detected. Thirteen strains had integrons with a single cassette: aac(3)-Ia (9 strains), ant(2")-Ia (2 strains), or aac(6′)-Ib (2 strains); 1 hadaac(6′)-Ib and oxa20cassettes and an unknown gene; and 1 had an integron containingant(2")-Ia and an oxa3cassette truncated by IS6100. The remaining strains harbored class 1 integrons with gene cassettes previously found inEnterobacteriaceae. One integron had a hybrid structure composed of intI2 and the 3′ conserved segment of class 1 integrons. These data indicate that integrons play a major role in multidrug resistance in Acinetobacter.


2005 ◽  
Vol 49 (2) ◽  
pp. 836-839 ◽  
Author(s):  
Patrícia Antunes ◽  
Jorge Machado ◽  
João Carlos Sousa ◽  
Luísa Peixe

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.


2002 ◽  
Vol 46 (8) ◽  
pp. 2400-2408 ◽  
Author(s):  
Sally R. Partridge ◽  
Christina M. Collis ◽  
Ruth M. Hall

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.


2001 ◽  
Vol 45 (4) ◽  
pp. 1305-1308 ◽  
Author(s):  
Beatriz Guerra ◽  
Sara M. Soto ◽  
Jose M. Argüelles ◽  
M. Carmen Mendoza

ABSTRACT A multidrug-resistant Salmonella enterica serotype [4,5,12:i:−] clone carried a class 1 integron harboringdfrA12 and aadA2 gene cassettes andbla TEM-1, aac(3)-IV,cmlA1, and tetA genes located in large plasmids of about 140 kb (carrying spv) or 120 kb (lackingspv). Several segregants, lacking multidrug resistance, contained a plasmid smaller than the parental one and no longer hybridized with probes for the lost resistances. The genes mediating resistance to ampicillin, chloramphenicol, and tetracycline in the [4,5,12:i:−] clone are different from those found in the pentadrug-resistant serotype Typhimurium DT104 clone.


2014 ◽  
Vol 60 (4) ◽  
pp. 237-242 ◽  
Author(s):  
Haifei Yang ◽  
Yachao Pan ◽  
Lifen Hu ◽  
Yanyan Liu ◽  
Ying Ye ◽  
...  

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.


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