Gene cassettes and cassette arrays in mobile resistance integrons.

By S. Partridge, G. Tsafnat, Enrico W. Coiera, J. Iredell. FEMS Microbiology Reviews, 2009

647 citations recorded by the source corpus.

Gene cassettes are small mobile elements, consisting of little more than a single gene and recombination site, which are captured by larger elements called integrons. Several cassettes may be inserted into the same integron forming a tandem array. The discovery of integrons in the chromosome of many species has led to the identification of thousands of gene cassettes, mostly of unknown function, while integrons associated with transposons and plasmids carry mainly antibiotic resistance genes and constitute an important means of spreading resistance. An updated compilation of gene cassettes found in sequences of such 'mobile resistance integrons' in GenBank was facilitated by a specially developed automated annotation system. At least 130 different (<98% identical) cassettes that carry known or predicted antibiotic resistance genes were identified, along with many cassettes of unknown function. We list exemplar GenBank accession numbers for each and address some nomenclature issues. Various modifications to cassettes, some of which may be useful in tracking cassette epidemiology, are also described. Despite potential biases in the GenBank dataset, preliminary analysis of cassette distribution suggests interesting differences between cassettes and may provide useful information to direct more systematic studies.

Subfields: Molecular Biology, Molecular Medicine

View Paper: https://www.semanticscholar.org/paper/8d760927a8d8c6bb189208458512ec361a69f759

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In Molecular Biology

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5. Jianqiang Su
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In Molecular Medicine

1. Yong-guan Zhu
2. M. Gillings
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Citations in the corpus

• Long-term field application of sewage sludge increases the abundance of antibiotic resistance genes in soil. (2016, background): “It has been demonstrated that MGEs, especially integrons can be used by bacteria to stockpile and express different exogenous resistance genes and are considered to play a central role in the worldwide problem of antibiotic resistance (Gaze et al., 2011; Gillings et al., 2008; Partridge et al., 2009”
• Urban wastewater treatment plants as hotspots for antibiotic resistant bacteria and genes spread into the environment: a review. (2013, background): “…encoding resistance to almost all antibiotic families, including beta-lactams, aminoglycosides, trimethoprim, chloramphenicol, fosfomycin, macrolides, lincosamides, rifampicin and quinolones, besides antiseptics as quaternary ammonium compounds (QACs) have been described (Partridge et al., 2009).”
• Gene flow, mobile genetic elements and the recruitment of antibiotic resistance genes into Gram-negative pathogens. (2011, background): “Why then are the class 1 integrons almost exclusively responsible for disseminating resistance genes by site-specific recombination in Gram-negative pathogens, and why are they so abundant in these same organisms (Partridge et al., 2009)?”
• Antimicrobial Resistance in Bacteria: Mechanisms, Evolution, and Persistence (2019, background): “Especially class 1 integrons are widely present in pathogens and gut commensals and overall, they have accumulated over 130 gene cassettes conferring resistance to most antibiotic classes (Partridge et al. 2009).”
• Antibiotic Resistance Mechanisms in Bacteria: Relationships Between Resistance Determinants of Antibiotic Producers, Environmental Bacteria, and Clinical Pathogens (2018, background): “A rather large pool of circular gene cassettes containing the attC site and the promoter-less resistance determinants for almost all classes of antibiotics used clinically are also known to exist in bacteria (Partridge et al., 2009).”
• Antibiotic resistance gene spread due to manure application on agricultural fields. (2011, background): “Interestingly, antibiotic resistance gene cassettes were primarily found on integrons located on transposons and plasmids, and much less on chromosomally located integrons [58], suggesting a selection for mobility of resistance genes in the antibiotic era.”
• Integrons: Past, Present, and Future (2014, background): “In all, some 130 different antibiotic resistance gene cassettes from clinical class 1 integrons are now known, along with a few other gene cassettes of unknown function (103).”
• Acquired Antibiotic Resistance Genes: An Overview (2011, methodology): “Currently, four classes are recognized; those carrying intI1 are defined as class 1, intI2 as class 2, intI3 as class 3, and intI4 as class 4 (Carattoli, 2001; Partridge et al., 2009).”
• Antimicrobial resistance in aquaculture: a crisis for concern (2020, background): “Later, Partridge et al. (2009) reported more than 130 gene cassettes that conferred resistance to antimicrobials such as trimethoprim (dfr), beta lactams(blaCARB-2, blaOXA, blaP1), chloramphenicol (catB), macrolides, aminoglycosides (aad, aac), erythromycin (ereA) foscomycin, quinolones, rifampicin…”