Transduction of multiple drug resistance of Salmonella enterica serovar typhimurium DT104

Schmieger, Horst

doi:10.1016/s0378-1097(98)00553-9

Cited by 53 publications

(58 citation statements)

References 8 publications

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“…The poor fit of Model 3 also suggests that the individual genetic elements within SGI1 are not subject to random re-assortment; rather, the SGI1 variants circulate in the population in a few fixed forms. This conclusion is consistent with the current thinking on the molecular biological aspects of DT104 [17,33]. Although Models 1 and 3 did not reflect the observed data in terms of the number of unique profiles generated, the inferred prevalence of the main genomic island (the full SGI1) was similar in all three models.…”

Section: Discussionsupporting

confidence: 84%

From phenotype to genotype: a Bayesian solution

et al. 2010

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The study of biological systems commonly depends on inferring the state of a 'hidden' variable, such as an underlying genotype, from that of an 'observed' variable, such as an expressed phenotype. However, this cannot be achieved using traditional quantitative methods when more than one genetic mechanism exists for a single observable phenotype. Using a novel latent class Bayesian model, it is possible to infer the prevalence of different genetic elements in a population given a sample of phenotypes. As an exemplar, data comprising phenotypic resistance to six antimicrobials obtained from passive surveillance of Salmonella Typhimurium DT104 are analysed to infer the prevalence of individual resistance genes, as well as the prevalence of a genomic island known as SGI1 and its variants. Three competing models are fitted to the data and distinguished between using posterior predictive p-values to assess their ability to predict the observed number of unique phenotypes. The results suggest that several SGI1 variants circulate in a few fixed forms through the population from which our data were derived. The methods presented could be applied to other types of phenotypic data, and represent a useful and generic mechanism of inferring the genetic population structure of organisms.

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Section: Discussionsupporting

confidence: 84%

From phenotype to genotype: a Bayesian solution

et al. 2010

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“…The sequence of the 142-bp fragment was highly similar to the segment of P22 phage (42). Recent reports have demonstrated that antimicrobial resistance genes are clustered in the genome of serotype Typhimurium DT104 and that these genes can be efficiently transduced by P22-like phages (35). The DT104 strain may carry a P22-like prophage in its genome, and such a prophage may confer horizontal transfer and further spread of resistance genes.…”

Section: Discussionmentioning

confidence: 86%

Molecular Typing and Epidemiological Study of Salmonella enterica Serotype Typhimurium Isolates from Cattle by Fluorescent Amplified-Fragment Length Polymorphism Fingerprinting and Pulsed-Field Gel Electrophoresis

Tamada¹,

Nakaoka

Nishimori

et al. 2001

J Clin Microbiol

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One hundred twenty Salmonella enterica serotype Typhimurium strains, including 103 isolates from cattle gathered between 1977 and 1999 in the prefecture located on the northern-most island of Japan, were analyzed by using fluorescent amplified-fragment length polymorphism (FAFLP) and pulsed-field gel electrophoresis (PFGE) to examine the genotypic basis of the epidemic. Among these strains, there were 17 FAFLP profiles that formed four distinct clusters (A, B, C, and D). Isolates that belonged to cluster A have become increasingly common since 1992 with the increase of bovine salmonellosis caused by serotype Typhimurium. PFGE resolved 25 banding patterns that formed three distinct clusters (I, II, and III). All the isolates that belonged to FAFLP cluster A, in which all the strains of definitive phage type 104 examined were included, were grouped into PFGE cluster I. Taken together, these results indicate that clonal exchange of serotype Typhimurium has taken place since 1992, and they show a remarkable degree of homogeneity at a molecular level among contemporary isolates from cattle in this region. Moreover, we have sequenced two kinds of FAFLP markers, 142-bp and 132-bp fragments, which were identified as a polymorphic marker of strains that belonged to clusters A and C, respectively. The sequence of the 142-bp fragment shows homology with a segment of P22 phage, and that of the 132-bp fragment shows homology with a segment of traG, which is an F plasmid conjugation gene. FAFLP is apparently as well suited for epidemiological typing of serotype Typhimurium as is PFGE, and FAFLP can provide a source of molecular markers useful for studies of genetic variation in natural populations of serotype Typhimurium.Salmonella infections in livestock have been a concern for both animal and human health. In particular, a common serotype causing salmonellosis in humans is Salmonella enterica serotype Typhimurium, a globally distributed zoonotic serotype that is common in both cattle and poultry. In order to study the epidemiology of its outbreaks and determine the source of contamination so that a recurrence can be avoided, detailed characterization is necessary. Although the majority of outbreaks in livestock are caused by a select number of serotypes, serotyping is not an adequate method for determination of the source of contamination during an outbreak. One subtyping method for epidemiological investigations of human and animal salmonellosis outbreaks is phage typing (3), which discriminates phenotypically at the intraserotype level. However, phage typing requires access to special reagents and a specialized laboratory and fails to reflect evolutionary relationships of bacterial strains. In the last decade, with the development of new techniques in molecular biology techniques, new approaches have become available. Widely used are plasmid analysis (29, 39), chromosomal fingerprinting by Southern hybridization (12,16,31,36,37), and macrorestriction analysis of chromosomal DNA by pulsed-field gel electrophoresis (PFGE) (...

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“…No experimental data in relation to the horizontal transfer of the resistance gene cluster has been reported so far. However, transduction experiments with a P22-like phage demonstrated a facilitated transduction of DT104 resistance to unrelated Salmonella recipient strains [81]. Furthermore, a putative resolvase gene, similar to tnpR of the Tn3 transposons, has been identified adjacent to the intI1 gene of the first integron in the DT104 pentaresistance gene cluster, suggesting that at least part of this complex structure might arise from a transposon (Chaslus-Dancla E., European Molecular Biology Laboratory (EMBL) accession no.…”

Section: Clustering Of Resistance Genesmentioning

confidence: 99%

Importance of integrons in the diffusion of resistance

2001

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Summary -Horizontal transfer of resistance genes is a successful mechanism for the transmission and dissemination of multiple drug resistance among bacterial pathogens. The impact of horizontally transmitted genetic determinants in the evolution of resistance is particularly evident when resistance genes are physically associated in clusters and transferred en bloc to the recipient cell. Recent advances in the molecular characterisation of antibiotic resistance mechanisms have highlighted the existence of genetic structures, called integrons, involved in the acquisition of resistance genes. These DNA elements have frequently been reported in multi-drug resistant strains isolated from animals and humans, and are located either on the bacterial chromosome or on broad-host-range plasmids. The role of integrons in the development of multiple resistance relies on their unique capacity to cluster and express drug resistance genes. Moreover, the spread of resistance genes among different replicons and their exchange between plasmid and bacterial chromosome are facilitated by the integration of integrons into transposable elements. The association of a highly efficient gene capture and expression system, together with the capacity for vertical and horizontal transmission of resistance genes represents a powerful weapon used by bacteria to combat the assault of antibiotics. antimicrobial resistance / integron / transposon / horizontal gene transferRésumé -Importance des intégrons dans la diffusion de la résistance. Le transfert horizontal de gènes est un mécanisme efficace pour la transmission et la dissémination, parmi les agents pathogènes bactériens, de résistances multiples aux antibiotiques. L'impact des déterminants génétiques transmis horizontalement dans l'évolution de la résistance est particulièrement évident lorsque les gènes de résistance sont physiquement regroupés, et transférés en bloc à la cellule réceptrice. Des avancées récentes dans la caractérisation moléculaire des mécanismes de résistance aux antibiotiques ont mis en évidence l'existence de structures génétiques, appelées intégrons, impliqués dans l'acquisition de gènes de résistance. Ces éléments d'ADN ont été fréquemment observés dans des souches bactériennes multi-résistantes isolées chez des animaux ou chez des humains, localisés soit sur le chromosome bactérien, soit sur des plasmides à large spectre d'hôte. Le rôle des intégrons dans le développement de la multi-résistance repose sur leur capacité unique à former des clusters de gènes et à exprimer des gènes Vet. Res. 32 (2001) 243-259 243

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Transduction of multiple drug resistance of Salmonella enterica serovar typhimurium DT104

Cited by 53 publications

References 8 publications

From phenotype to genotype: a Bayesian solution

From phenotype to genotype: a Bayesian solution

Molecular Typing and Epidemiological Study of Salmonella enterica Serotype Typhimurium Isolates from Cattle by Fluorescent Amplified-Fragment Length Polymorphism Fingerprinting and Pulsed-Field Gel Electrophoresis

Importance of integrons in the diffusion of resistance

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