Class 1 integrons and plasmid-mediated multiple resistance genes of the Campylobacter species from pediatric patient of a university hospital in Taiwan

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.

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Diversity of antimicrobial resistance genes and class-1-integrons in phylogenetically related porcine and human Escherichia coli

Veterinary Microbiology ◽

10.1016/j.vetmic.2012.06.010 ◽

2012 ◽

Vol 160 (3-4) ◽

pp. 403-412 ◽

Cited By ~ 9

Author(s):

Christina Susanne Hölzel ◽

Katrin Susanne Harms ◽

Johann Bauer ◽

Ilse Bauer-Unkauf ◽

Stefan Hörmansdorfer ◽

...

Keyword(s):

Escherichia Coli ◽

Antimicrobial Resistance ◽

Resistance Genes ◽

Class 1 Integrons ◽

Antimicrobial Resistance Genes ◽

Class 1

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The cfr and cfr-like multiple resistance genes

Research in Microbiology ◽

10.1016/j.resmic.2017.12.003 ◽

2018 ◽

Vol 169 (2) ◽

pp. 61-66 ◽

Cited By ~ 11

Author(s):

Birte Vester

Keyword(s):

Resistance Genes ◽

Multiple Resistance ◽

Multiple Resistance Genes

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The Evolution of Class 1 Integrons and the Rise of Antibiotic Resistance

Journal of Bacteriology ◽

10.1128/jb.00152-08 ◽

2008 ◽

Vol 190 (14) ◽

pp. 5095-5100 ◽

Cited By ~ 245

Author(s):

Michael Gillings ◽

Yan Boucher ◽

Maurizio Labbate ◽

Andrew Holmes ◽

Samyuktha Krishnan ◽

...

Keyword(s):

Antibiotic Resistance ◽

Resistance Genes ◽

Antibiotic Resistance Genes ◽

Lateral Transfer ◽

Natural Environments ◽

Class 1 Integrons ◽

Wide Range ◽

Human Food Chain ◽

Class 1 ◽

Phylogenetic Signature

ABSTRACT Class 1 integrons are central players in the worldwide problem of antibiotic resistance, because they can capture and express diverse resistance genes. In addition, they are often embedded in promiscuous plasmids and transposons, facilitating their lateral transfer into a wide range of pathogens. Understanding the origin of these elements is important for the practical control of antibiotic resistance and for exploring how lateral gene transfer can seriously impact on, and be impacted by, human activities. We now show that class 1 integrons can be found on the chromosomes of nonpathogenic soil and freshwater Betaproteobacteria. Here they exhibit structural and sequence diversity, an absence of antibiotic resistance genes, and a phylogenetic signature of lateral transfer. Some examples are almost identical to the core of the class 1 integrons now found in pathogens, leading us to conclude that environmental Betaproteobacteria were the original source of these genetic elements. Because these elements appear to be readily mobilized, their lateral transfer into human commensals and pathogens was inevitable, especially given that Betaproteobacteria carrying class 1 integrons are common in natural environments that intersect with the human food chain. The strong selection pressure imposed by the human use of antimicrobial compounds then ensured their fixation and global spread into new species.

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Incidence, Distribution, and Spread of Tetracycline Resistance Determinants and Integron-Associated Antibiotic Resistance Genes among Motile Aeromonads from a Fish Farming Environment

Applied and Environmental Microbiology ◽

10.1128/aem.67.12.5675-5682.2001 ◽

2001 ◽

Vol 67 (12) ◽

pp. 5675-5682 ◽

Cited By ~ 178

Author(s):

Anja S. Schmidt ◽

Morten S. Bruun ◽

Inger Dalsgaard ◽

Jens L. Larsen

Keyword(s):

Antibiotic Resistance ◽

Resistance Gene ◽

Resistance Genes ◽

Antibiotic Resistance Genes ◽

Tetracycline Resistance ◽

Class 1 Integron ◽

Gene Cassettes ◽

Class 1 Integrons ◽

Resistance Determinants ◽

Class 1

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.

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