scholarly journals Characterisation of drug resistance gene cassettes associated with class 1 integrons in clinical isolates of Escherichia coli from Taiwan, ROC

2000 ◽  
Vol 49 (12) ◽  
pp. 1097-1102 ◽  
Author(s):  
CHUNG-YU CHANG ◽  
YU-HUNG CHANG ◽  
LIN-LI CHANG ◽  
SHUI-FENG CHANG ◽  
TSONG-MING LEE
2005 ◽  
Vol 49 (6) ◽  
pp. 2522-2524 ◽  
Author(s):  
Jin-Yong Jeong ◽  
Hyun Jung Yoon ◽  
Eun Sil Kim ◽  
Yoola Lee ◽  
Sang-Ho Choi ◽  
...  

ABSTRACT qnr was detected in 2 of 260 Escherichia coli clinical isolates collected from a Korean hospital during the period 2001 to 2003. The two strains were not clonally related. qnr was located in In4 family class 1 integrons of original structure, downstream of orf513 and upstream from another resistance gene (dfrA3b) and a gene of unknown function (orf105). Transfer of the qnr determinant by conjugation could be detected from only one strain.


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.


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.


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.


2020 ◽  
Author(s):  
Chinyere B. Chigor ◽  
Ini-Abasi I. Ibangha ◽  
Nkechinyere O. Nweze ◽  
Chizoba A. Ozochi ◽  
Valentino C. Onuora ◽  
...  

AbstractIn spite of treated wastewater presenting itself as an attractive alternative to scarce quality water in the developing countries, the associated contamination of fresh produce by irrigation waters leading to outbreak of foodborne illnesses is on the rise. Horizontal transfer of integrons play important role in the spread and maintenance of antimicrobial resistance among strains of Escherichia coli. This study assessed the effluents from the University of Nigeria, Nsukka Wastewater Treatment Plant (UNN-WWTP) as well as vegetables irrigated with the effluent, and vegetables sold in selected markets from Nsukka and Enugu cities for the presence of E. coli and determined the prevalence integrons in multidrug-resistant isolates. Isolation of E. coli was done using eosin methylene blue agar and isolates subjected to Gram staining for identification of presumptive colonies. Confirmation of E. coli was achieved by polymerase chain reaction (PCR) technique, targeting beta-glucuronidase (uidA). Resistance to antibiotics was determined using the Bauer-Kirby disk diffusion assay and the Clinical and Laboratory Standard Institute criteria. Integrons were detected by multiplex PCR using primers specific for class 1 and 2 integrons. A total of 178 E. coli isolates were obtained from WWTP effluent (41), and vegetables from greenhouse (46), farms (55) and market (36). Multi-drug resistance was detected in all the isolates, ranging from five-drug resistance in a single isolate to 16-drug resistance patterns in two different isolates. Of the total isolates, class 1 integrons were abundantly detected in 175 (98.3%) and class 2 in 5 (2.8%). All the class 2 integrons were found in isolates that were positive for class 1. The high detection of E. coli in the studied effluent and vegetables pose potential public health hazards heightened by observed multidrug resistance in all the isolates and the high prevalence of class 1 integron. It is concluded that the vegetable samples are significant reservoirs for potentially pathogenic E. coli. Therefore, vegetable irrigation farming with unsafe water should be discontinued, while appropriate improvement strategies to ensure compliance should be facilitated without further delay.


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