The Butyrivibrio fibrisolvens tet (W) Gene Is Carried on the Novel Conjugative Transposon Tn B1230 , Which Contains Duplicated Nitroreductase Coding Sequences

Abstract

The Butyrivibrio fibrisolvens tet(W) gene is located on the conjugative transposon TnB1230. TnB1230 encodes transfer proteins with 48 to 67% identity to some of those encoded by Tn1549. tet(W) is flanked by directly repeated sequences with significant homology to oxygen-insensitive nitroreductases. The 340 nucleotides upstream of tet(W) are strongly conserved and are required for tetracycline resistance.Tetracyclines are the second most widely used group of antibiotics worldwide, and tetracycline resistance (Tc r ) is extremely common among bacteria (17). Many Tc r genes are transmissible, being carried by plasmids or transposable chromosomal elements. Tc r genes have mainly been described for pathogenic bacteria, but the new resistance genes tet(W) (2, 20) and tet(32) (12) were first identified in anaerobic commensal bacteria from the rumen and from porcine and human feces. These genes are distinct from previously described ribosome protection genes, with the highest identities being 68% [to Tet(W)] and 76% [to Tet(32)] at the corresponding amino acid level. tet(W) is one of the most widespread tetracycline resistance genes in environmental samples (1,23).Copies of tet(W) found in environmentally and phylogenetically distinct bacterial isolates (2, 20) have remarkable sequence conservation, which argues for the extensive rapid transfer of this gene in nature. Previous work showed that tet(W) could be transferred at high frequencies (10 Ϫ2 to 10 Ϫ5

Tetracycline Resistome of the Organic Pig Gut

“…1). Structurally, these genes were 96 to 99% identical to the previously described tet(W) genes (3,6,14,18,29,32). The 657-bp upstream region in clone 10 was 99% identical to the corresponding regions in Arcanobacterium pyogenes strains OX9 and OX4 (DQ519394 and DQ517519) (6) (Fig.…”

Antibiotic Resistance Characteristics of Environmental Bacteria from an Oxytetracycline Production Wastewater Treatment Plant and the Receiving River

“…With increasing screening, tet(A) and tet(W) have been identified in more and more bacterial genera or species. The association of these genes with plasmids and conjugative transposons may underlie their wide distribution in the current and previous studies (31,44). Many tet genes have been linked to mobile genetic elements like integrons, plasmids, or transposons (2,6,37).…”

Antibiotic Susceptibility of Bifidobacterial Strains Distributed in the Japanese Market

“…In Butyrivibrio fibrisolvens, the tet(W) gene is integrated in conjugative transposon TnB1230 which is thought to be responsible for the environmental dissemination of tet(W) and has been demonstrated to be transferable to a recipient. 37) Over the last few years, tet(W) has been isolated from a broad spectrum of bacterial genera and is now considered to have the largest host range among the tetracycline resistance genes. 36) Its association with conjugative transposons and its frequent presence in the intestinal and oral flora of humans and animals strongly suggest its transferability.…”

“…The suspension was diluted 500 times in a double-fold concentrated MRS-cys medium, and 100 ml of the diluted suspension was distributed to each well of a 96-well microplate. After incubating under anaerobic conditions at 37 C for 48 h, the bacterial growth was similarly measured by a spectrophotometer with the method already described for absorption at 650 nm. Each strain was tested in two or three independent experiments.…”