Recovery of diverse genes for class 1 integron-integrases from environmental DNA samples

Gillings, Michael R.; Krishnan, Samyuktha; Worden, Paul; Hardwick, Simon A.

doi:10.1111/j.1574-6968.2008.01291.x

Cited by 68 publications

(61 citation statements)

References 30 publications

(37 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Although this correlation was not as strong as other study , the high abundance of intI1 and correlation with abundance of ARGs could suggest that intI1 may play certain role in the dissemination of ARGs, thus indicating that horizontal gene transfer could be an important pathway for ARG proliferation, especially under antibiotic selection pressure (Ochman et al, 2000). Previous study also demonstrated that class 1 integrons are an important vector for the propagation of antibiotic resistance (Gillings et al, 2008).…”

Section: Relationship Between Args and Environmental Factors Or Inti1mentioning

confidence: 54%

Impact of reclaimed water irrigation on antibiotic resistance in public parks, Beijing, China

Wang

Qiao

et al. 2014

Environmental Pollution

146

View full text Add to dashboard Cite

a b s t r a c tThe abundance and distribution of antibiotics and antibiotic resistance genes (ARGs) in soils from six parks using reclaimed water in Beijing, China, were characterized. Three classes of commonly used antibiotics (tetracycles, quinolones, and sulfonamides) were analyzed by liquid chromatography-tandem mass spectrometry (LC-MS/MS). The highest concentrations of tetracyclines and quinolones were 145.2 mg kg À1 and 79.2 mg kg À1 , respectively. Detected tetG, tetW, sulI, and sulII genes were quantified by quantitative PCR. ARGs exhibited various abundances for different park soils. The integrase gene (intI1) as an indicator of horizontal gene transfer potential was also detected in high abundance, and had significant positive correlation with tetG, sulI, and sulII genes, suggesting that intI1 may be involved in ARGs dissemination. Both sulII and intI1 clones had high homology with some classes of pathogenic bacteria, such as Klebsiella oxytoca, Acinetobacter baumannii, Shigella flexneri, which could trigger potential public health concern.

show abstract

Section: Relationship Between Args and Environmental Factors Or Inti1mentioning

confidence: 54%

Impact of reclaimed water irrigation on antibiotic resistance in public parks, Beijing, China

Wang

Qiao

et al. 2014

Environmental Pollution

146

View full text Add to dashboard Cite

show abstract

“…5). Examination of metagenomic DNA recovers diverse class 1 integron integrase genes, many with less than 95% nucleotide sequence identity (127). In contrast, the integron integrase genes in all class 1 integrons from clinical sources are essentially identical, strongly suggesting that all clinical class 1 integrons are recent descendants of a single event involving just one representative of the diverse intI1 sequence variants present in natural environments.…”

Section: Origin Of Class 1 Integrons As Vectors For Antibiotic Resistmentioning

confidence: 99%

“…These chromosomal integrons carry gene cassettes of unknown function and exhibit significant sequence diversity in their IntI1 genes (30,34,127). All chromosomal class 1 integrons characterized from environmental sources have common terminal sequences.…”

Section: Origin Of Class 1 Integrons As Vectors For Antibiotic Resistmentioning

confidence: 99%

Integrons: Past, Present, and Future

Gillings

2014

Microbiol Mol Biol Rev

Self Cite

562

472

View full text Add to dashboard Cite

SUMMARY Integrons are versatile gene acquisition systems commonly found in bacterial genomes. They are ancient elements that are a hot spot for genomic complexity, generating phenotypic diversity and shaping adaptive responses. In recent times, they have had a major role in the acquisition, expression, and dissemination of antibiotic resistance genes. Assessing the ongoing threats posed by integrons requires an understanding of their origins and evolutionary history. This review examines the functions and activities of integrons before the antibiotic era. It shows how antibiotic use selected particular integrons from among the environmental pool of these elements, such that integrons carrying resistance genes are now present in the majority of Gram-negative pathogens. Finally, it examines the potential consequences of widespread pollution with the novel integrons that have been assembled via the agency of human antibiotic use and speculates on the potential uses of integrons as platforms for biotechnology.

show abstract

“…Samples included stream sediments from Cowan Creek, North Turramurra (RA: Hardwick et al, 2008), biofilms from Mars Creek, North Ryde (BF: Gillings et al, 2008b), contaminated soil from Balmain (BAL; Yeates and Gillings, 1998), biofilms from a groundwater treatment plant in Botany (OR: Gillings et al, 2006) This element carries the terminal inverted repeats (IRi and IRt), a class 1 integron integrase gene (intI1), a primary recombination site (attI; small diamond), a cassette array (usually encoding antibiotic resistance) with each cassette bounded by secondary recombination sites (attC; circles), a cassette for quaternary ammonium compound resistance (qacE) and a transposition module (tni). (b) An environmental class 1 integron embedded into a bacterial chromosome carries the integrase gene, flanking regions and a cassette array that does not usually encode antibiotic resistance.…”

Section: Methodsmentioning

confidence: 99%

Gene cassettes encoding resistance to quaternary ammonium compounds: a role in the origin of clinical class 1 integrons?

et al. 2008

View full text Add to dashboard Cite

DNA sequencing, phylogenetic and mapping studies suggest that the class 1 integron found in pathogens arose when one member of the diverse family of environmental class 1 integrons became embedded into a Tn402 transposon. However, the timing of this event and the selective forces that first fixed the newly formed element in a bacterial lineage are still unknown. Biocides have a longer use in clinical practice than antibiotics, and a qac (quaternary ammonium compound) resistance gene, or remnant thereof, is a normal feature of class 1 integrons recovered from clinical isolates. Consequently, it is possible that the initial selective advantage was conferred by resistance to biocides, mediated by qac. Here, we show that diverse qac gene cassettes are a dominant feature of cassette arrays from environmental class 1 integrons, and that they occur in the absence of any antibiotic resistance gene cassettes. They are present in arrays that are dynamic, acquiring and rearranging gene cassettes within the arrays. The abundance of qac gene cassettes makes them a likely candidate for participation in the original insertion into Tn402, and as a source of a readily selectable phenotype. More broadly, the increasing use of qac and other biocides at the present time seems likely to promote the fixation of further novel genetic elements, with unpredictable and potentially adverse consequences for human health and agriculture.

show abstract

Recovery of diverse genes for class 1 integron-integrases from environmental DNA samples

Cited by 68 publications

References 30 publications

Impact of reclaimed water irrigation on antibiotic resistance in public parks, Beijing, China

Impact of reclaimed water irrigation on antibiotic resistance in public parks, Beijing, China

Integrons: Past, Present, and Future

Gene cassettes encoding resistance to quaternary ammonium compounds: a role in the origin of clinical class 1 integrons?

Contact Info

Product

Resources

About