First report of a Tn402-like class 1 integron carrying blaVIM-2 in Pseudomonas putida from Argentina

Marchiaro, Patricia; Viale, Alejandro M.; Ballerini, Viviana; Rossignol, Gustavo; Vila, A.J.; Limansky, Adriana S.

doi:10.3855/jidc.1012

Cited by 25 publications

(22 citation statements)

References 15 publications

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“…Consequently, testing for other variants, most notably those with a complete transposition module (Post et al , 2007), would be highly desirable. Putting aside differences in the inserted cassette arrays, more than one functional transposon version has been identified (Labbate et al , 2008; Marchiaro et al , 2010). One of these, Tn 6007 , is from a human commensal bacterium and the associated integron has a complete tni module that is a hybrid when compared with Tn 402 (Labbate et al , 2008).…”

Section: Integronsmentioning

confidence: 99%

Gene flow, mobile genetic elements and the recruitment of antibiotic resistance genes into Gram-negative pathogens

2011

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Antibiotics were one of the great discoveries of the 20th century. However, resistance appeared even in the earliest years of the antibiotic era. Antibiotic resistance continues to become worse, despite the ever-increasing resources devoted to combat the problem. One of the most important factors in the development of resistance to antibiotics is the remarkable ability of bacteria to share genetic resources via Lateral Gene Transfer (LGT). LGT occurs on a global scale, such that in theory, any gene in any organism anywhere in the microbial biosphere might be mobilized and spread. With sufficiently strong selection, any gene may spread to a point where it establishes a global presence. From an antibiotic resistance perspective, this means that a resistance phenotype can appear in a diverse range of infections around the globe nearly simultaneously. We discuss the forces and agents that make this LGT possible and argue that the problem of resistance can ultimately only be managed by understanding the problem from a broad ecological and evolutionary perspective. We also argue that human activities are exacerbating the problem by increasing the tempo of LGT and bacterial evolution for many traits that are important to humans.

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Section: Integronsmentioning

confidence: 99%

Gene flow, mobile genetic elements and the recruitment of antibiotic resistance genes into Gram-negative pathogens

2011

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“…The 3′-CS region has been suggested to be the result of a fusion of the qacE gene of the Tn 402 transposon with the sulI gene, with consequent partial deletion of the qacE gene; that occurred at the same time as a deletion event in the transposition functions of the Tn 402 transposon, resulting in a structure unable of self-mobilization 25 . In fact, most C1 integrons are defective transposons; 26 though a few C1 integrons with a complete transposition module have been identified 27 , 28 . After initial formation of C1 integrons, strong selection for resistance to antimicrobials has favored events of capture of antibiotic resistance gene cassettes resulting in the compositions of C1 integron as we know them today 4 , 18 .…”

Section: Integronsmentioning

confidence: 99%

Integrons

Domingues

Silva

Nielsen

2012

Mobile Genetic Elements

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Integrons are genetic elements first described at the end of the 1980s. Although most integrons were initially described in human clinical isolates, they have now been identified in many non-clinical environments, such as water and soil. Integrons are present in ≈10% of the sequenced bacterial genomes and are frequently linked to mobile genetic elements (MGEs); particularly the class 1 integrons. Genetic linkage to a diverse set of MGEs facilitates horizontal transfer of class 1 integrons within and between bacterial populations and species. The mechanistic aspects limiting transfer of MGEs will therefore limit the transfer of class 1 integrons. However, horizontal movement due to genes provided in trans and homologous recombination can result in class 1 integron dynamics independent of MGEs. A key determinant for continued dissemination of class 1 integrons is the probability that transferred MGEs will be vertically inherited in the recipient bacterial population. Heritability depends both on genetic stability as well as the fitness costs conferred to the host. Here we review the factors known to govern the dissemination of class 1 integrons in bacteria.

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“…Several genetic structures have been described at the 3′ end of the variable region of class 1 integrons [22], [23], [24], [25], [26], [27], [28]. There are three genetic platforms containing and spreading the class 1 integrons described in clinical samples from Argentina (Figure 1): (i) the most common one exhibits the well-known 3′- c onserved s egment (3′-CS) at the end of the variable region, which contains the qacE Δ 1 gene that is a deleted form of the quaternary ammonium compounds resistance gene cassette, qacE , followed by the sul1 gene that confers resistance to sulphonamides, and finally the orf5 of unknown function [12] (Figure 1A); (ii) the complete or incomplete module of Tn 402 , tniC - tniQ - tniB - tniA [29] (Figure 1B); and (iii) the 3′-CS can be invaded by the putative site-specific recombinase IS CR1 , which adds a second variable region that can contain an important variety of antimicrobial resistance genes such as bla CTX-M-2 and qnrB10 , which are known as unusual or complex class 1 integrons [30], [31], [32], [33] (Figure 1C). Neither class 1 integrons nor unusual class 1 integrons allow intracellular mobilization of the intI1 gene per se .…”

Section: Introductionmentioning

confidence: 99%

Class 1 Integrons in Environments with Different Degrees of Urbanization

et al. 2012

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Background Class 1 integrons are one of the most successful elements in the acquisition, expression and spread of antimicrobial resistance genes (ARG) among clinical isolates. Little is known about the gene flow of the components of the genetic platforms of class 1 integrons within and between bacterial communities. Thus it is important to better understand the interactions among “environmental” intI1 , its genetic platforms and its distribution with human activities. Methodology/Principal Findings An evaluation of two types of genetic determinants, ARG ( sul1 and qacE1 / qacE Δ 1 genes) and lateral genetic elements (LGE) ( intI1 , IS CR1 and tniC genes) in a model of a culture-based method without antibiotic selection was conducted in a gradient of anthropogenic disturbances in a Patagonian island recognized as being one of the last regions containing wild areas. The intI1 , IS CR1 genes and intI1 pseudogenes that were found widespread throughout natural communities were not associated with urbanization (p>0.05). Each ARG that is embedded in the most common genetic platform of clinical class 1 integrons, showed different ecological and molecular behaviours in environmental samples. While the sul1 gene frequency was associated with urbanization, the qacE1 / qacE Δ 1 gene showed an adaptive role to several habitats. Conclusions/Significance The high frequency of intI1 pseudogenes suggests that, although intI1 has a deleterious impact within several genomes, it can easily be disseminated among natural bacterial communities. The widespread occurrence of IS CR1 and intI1 throughout Patagonian sites with different degree of urbanization, and within different taxa, could be one of the causes of the increasing frequency of multidrug-resistant isolates that have characterized Argentina for decades. The flow of ARG and LGE between natural and clinical communities cannot be explained with a single general process but is a direct consequence of the interaction of multiple factors operating at molecular, ecological, phylogenetic and historical levels.

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First report of a Tn402-like class 1 integron carrying blaVIM-2 in Pseudomonas putida from Argentina

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Cited by 25 publications

References 15 publications

Gene flow, mobile genetic elements and the recruitment of antibiotic resistance genes into Gram-negative pathogens

Gene flow, mobile genetic elements and the recruitment of antibiotic resistance genes into Gram-negative pathogens

Integrons

Class 1 Integrons in Environments with Different Degrees of Urbanization

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