scholarly journals Tetracycline Resistome of the Organic Pig Gut

2009 ◽  
Vol 75 (6) ◽  
pp. 1717-1722 ◽  
Author(s):  
Katarzyna A. Kazimierczak ◽  
Karen P. Scott ◽  
Denise Kelly ◽  
Rustam I. Aminov
Keyword(s):  
Resistance Genes ◽  
Metagenomic Library ◽  
Antibiotic Resistance Genes ◽  
Artificial Chromosome ◽  
Mobile Genetic Elements ◽  
Structure Characteristic ◽  
Genetic Elements ◽  
Genes Encoding ◽  
Flanking Regions ◽  
Metagenomic Approach

ABSTRACT The occurrence of genes conferring resistance to tetracyclines in the organic pig gut was assessed through the metagenomic approach. Of 9,000 bacterial artificial chromosome clones analyzed, 10 were identified as carrying the known tet(C), tet(W), and tet(40) genes, as well as novel genes encoding resistance to the tetracyclines minocycline and doxycycline. The latter are different from the known tet genes and are homologous to genes encoding UDP-glucose 4-epimerases, with the domain structure characteristic for these enzymes. The majority of the resistance genes were associated with putative mobile genetic elements. The sequence of a novel 9.7-kb plasmid carrying tet(W) and tet(40) was also identified. Conserved flanking regions identified around the tet(W) and tet(40) genes in our metagenomic library may play a role in genetic exchange of these genes. This is the first report describing the occurrence of tet(40) outside the human intestine. The maintenance of antibiotic resistance genes in apparently antibiotic-free animals is probably due to their presence on mobile genetic elements, the fitness cost of which for the cell is ameliorated during the previous antibiotic selection.

scholarly journals Cargo genes of Tn7-like transposons comprise an enormous diversity of defense systems, mobile genetic elements and antibiotic resistance genes

2021 ◽  
Author(s):  
Sean Benler ◽  
Guilhem Faure ◽  
Han-Altae Tran ◽  
Sergey Shmakov ◽  
Feng Zhang ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Resistance Genes ◽  
Large Scale ◽  
Antibiotic Resistance Genes ◽  
Mobile Genetic Elements ◽  
Central Carbon Metabolism ◽  
Genetic Elements ◽  
Major Mechanism ◽  
Metabolism Enzymes ◽  
Genes Encoding

Transposition is a major mechanism of horizontal gene mobility in prokaryotes. However, exploration of the genes mobilized by transposons (cargo) is hampered by the difficulty in delineating integrated transposons from their surrounding genetic context. Here, we present a computational approach that allowed us to identify the boundaries of 6,549 Tn7-like transposons at base pair resolution. We found that 96% of these transposons carry at least one cargo gene. Delineation of distinct communities in a gene-sharing network demonstrates how transposons function as a conduit of genes between phylogenetically distant hosts. Comparative analysis of the cargo genes reveals significant enrichment of mobile genetic elements (MGEs) nested within Tn7-like transposons, such as insertion sequences and toxin-antitoxin modules, genes involved in recombination and anti-MGE defense, and in antibiotic resistance. More unexpectedly, cargo also includes genes encoding central carbon metabolism enzymes. Twenty-two Tn7-like transposons carry both an anti-MGE defense system and antibiotic resistance genes, illustrating how bacteria can overcome these combined pressures upon acquisition of a single transposon. This work substantially expands the distribution of Tn7-like transposons, defines their evolutionary relationships and provides a large-scale functional classification of prokaryotic genes mobilized by transposition.

scholarly journals Detection of a Novel, and Likely Ancestral, Tn916-Like Element from a Human Saliva Metagenomic Library

Genes ◽  
2020 ◽  
Vol 11 (5) ◽  
pp. 548
Author(s):  
Liam J. Reynolds ◽  
Muna F. Anjum ◽  
Adam P. Roberts
Keyword(s):  
Resistance Genes ◽  
Metagenomic Library ◽  
Tetracycline Resistance ◽  
Human Saliva ◽  
Fusion Event ◽  
Tetracycline Resistance Genes ◽  
Antimicrobial Resistance Genes ◽  
Genes Encoding ◽  
Gene Fusion Event ◽  
Metagenomic Approach

Tn916 is a conjugative transposon (CTn) and the first reported and most well characterised of the Tn916/Tn1545 family of CTns. Tn916-like elements have a characteristic modular structure and different members of this family have been identified based on similarities and variations in these modules. In addition to carrying genes encoding proteins required for their conjugation, Tn916-like elements also carry accessory, antimicrobial resistance genes; most commonly the tetracycline resistance gene, tet(M). Our study aimed to identify and characterise tetracycline resistance genes from the human saliva metagenome using a functional metagenomic approach. We identified a tetracycline-resistant clone, TT31, the sequencing of which revealed it to encode both tet(M) and tet(L). Comparison of the TT31 sequence with the accessory, regulation, and recombination modules of other Tn916-like elements indicated that a partial Tn916-like element encoding a truncated orf9 was cloned in TT31. Analysis indicated that a previous insertion within the truncated orf9 created the full length orf9 found in most Tn916-like transposons; demonstrating that orf9 is, in fact, the result of a gene fusion event. Thus, we hypothesise that the Tn916-like element cloned in TT31 likely represents an ancestral Tn916.

scholarly journals Sludge bio-drying: Effective to reduce both antibiotic resistance genes and mobile genetic elements

2016 ◽  
Vol 106 ◽  
pp. 62-70 ◽  
Author(s):  
Junya Zhang ◽  
Qianwen Sui ◽  
Juan Tong ◽  
Chulu Buhe ◽  
Rui Wang ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Resistance Genes ◽  
Antibiotic Resistance Genes ◽  
Mobile Genetic Elements ◽  
Genetic Elements
Sign in / Sign up

Export Citation Format

Share Document