Presence of chromosomal elements resembling the composite structure Tn3701 in streptococci

Bouguénec, Chantal Le; Cespédès, Gilda de; Horaud, T

doi:10.1128/jb.172.2.727-734.1990

Cited by 71 publications

(66 citation statements)

References 41 publications

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“…These composite gram-positive elements are Ն50 kb and have been found in streptococci and enterococci. The prototype of the composite element is Tn3701, first described in S. pyogenes (140). In some of these composite elements, the central Tn916-like element can be removed and the nonhomologous segment can undergo conjugative transposition independently, as occurs in Tn5253 from S. pneumoniae (48).…”

Section: Distribution and Mobility Of Tet Genesmentioning

confidence: 99%

“…In addition, multiple conjugative transposons, which have one complete transposon inserted within another transposon, have been described in some of the cocci. These can transfer as a single unit, or the inserted transposon can be transferred separately, giving flexibility for transfer of antibiotic resistance genes (48,140). Selection for any antibiotic on these multiple-drug-resistant units normally selects for the entire unit and may explain why the isolation of Tc r S. pneumoniae in children occurs even though tetracycline is not used in this age group (162,289).…”

Section: Incidence Of Tetracycline Resistancementioning

confidence: 99%

“…Many examples exist in the literature for the gramnegative genera Haemophilus (168), Neisseria (132), and Bacteriodes (45,57,143) and for gram-positive genera such as Streptococcus, which all carry the same tet genes as their pathogenic and opportunistic related species (45,74,140) Commensal Neisseria species carry an incomplete tet(M) transposon integrated into their chromosomal DNA while the pathogenic N. gonorrhoeae and N. meningitidis carry an incomplete tet(M) transposon integrated on a 25.2-MDa plasmid of gonococcal origin (132,223). However, in the laboratory the 25.2-MDa plasmid can be transferred and maintained in the commensal Neisseria spp.…”

Section: Incidence Of Tetracycline Resistancementioning

confidence: 99%

“…The structural organization of these composite elements varies. Both the composite and Tn916 families of elements can carry antibiotic resistance genes which confer resistance to chloramphenicol, erythromycin, and kanamycin, in addition to the tet(M) gene, which confers resistance to both tetracycline and minocycline (48,140).…”

Section: Distribution and Mobility Of Tet Genesmentioning

confidence: 99%

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Tetracycline Antibiotics: Mode of Action, Applications, Molecular Biology, and Epidemiology of Bacterial Resistance

Chopra

Roberts

2001

Microbiol Mol Biol Rev

3,630

2,643

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Tetracyclines were discovered in the 1940s and exhibited activity against a wide range of microorganisms including gram-positive and gram-negative bacteria, chlamydiae, mycoplasmas, rickettsiae, and protozoan parasites. They are inexpensive antibiotics, which have been used extensively in the prophlylaxis and therapy of human and animal infections and also at subtherapeutic levels in animal feed as growth promoters. The first tetracycline-resistant bacterium, Shigella dysenteriae, was isolated in 1953. Tetracycline resistance now occurs in an increasing number of pathogenic, opportunistic, and commensal bacteria. The presence of tetracycline-resistant pathogens limits the use of these agents in treatment of disease. Tetracycline resistance is often due to the acquisition of new genes, which code for energy-dependent efflux of tetracyclines or for a protein that protects bacterial ribosomes from the action of tetracyclines. Many of these genes are associated with mobile plasmids or transposons and can be distinguished from each other using molecular methods including DNA-DNA hybridization with oligonucleotide probes and DNA sequencing. A limited number of bacteria acquire resistance by mutations, which alter the permeability of the outer membrane porins and/or lipopolysaccharides in the outer membrane, change the regulation of innate efflux systems, or alter the 16S rRNA. New tetracycline derivatives are being examined, although their role in treatment is not clear. Changing the use of tetracyclines in human and animal health as well as in food production is needed if we are to continue to use this class of broad-spectrum antimicrobials through the present century

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Section: Distribution and Mobility Of Tet Genesmentioning

confidence: 99%

Section: Incidence Of Tetracycline Resistancementioning

confidence: 99%

Section: Incidence Of Tetracycline Resistancementioning

confidence: 99%

Section: Distribution and Mobility Of Tet Genesmentioning

confidence: 99%

See 2 more Smart Citations

Tetracycline Antibiotics: Mode of Action, Applications, Molecular Biology, and Epidemiology of Bacterial Resistance

Chopra

Roberts

2001

Microbiol Mol Biol Rev

3,630

2,643

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“…Two genes that encode resistance to tetracycline are considered to be part of the same class if they are shown to cross-hybridize by Southern analysis. Three classes of ribosome protection mechanisms have been reported: Tet M, Tet 0, and Tet Q. Tet M represents the most widespread tetracycline determinant, as it has been isolated from a wide range of grampositive, as well as gram-negative, bacteria (2,3,5,7,8,18,22,(29)(30)(31). The Tet 0 determinant found in streptococci (21) and campylobacters (25) codes for resistance to all tetracycline antibiotics, including minocycline.…”

mentioning

confidence: 99%

Sequencing of a tet(Q) gene isolated from Bacteroides fragilis 1126

Lépine

Lacroix

Walker

et al. 1993

Antimicrob Agents Chemother

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Recently, Tet Q, a tetracycline resistance determinant that confers resistance by a ribosome protection mechanism, was described and added to the two previously described classes, Tet M and Tet O. The first representative of this class, tetA(Q)1, was isolated from Bacteroides thetaiotaomicron DOT. We report the sequencing of a gene isolated from B. fragilis 1126 which also confers tetracycline resistance. Because of its high degree of identity (97%) with the tetA(Q)1 gene, we defined it as tetA(Q)2. MIC studies revealed that tetA(Q)2 provides a low level of resistance to tetracycline when cloned into Escherichia coli. The extensive homology between tetA(Q)1 and tetA(Q)2 supports the idea of a recent horizontal transfer of tet(Q) genes among Bacteroides spp.

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