Dataset Information

New tetracycline resistance determinants coding for ribosomal protection in streptococci and nucleotide sequence of tet(T) isolated from Streptococcus pyogenes A498.

ABSTRACT: An approach based on PCR has been developed to identify new members of the tet gene family in streptococci resistant to tetracycline and minocycline. Degenerate primers, corresponding to portions of the conserved domains of the proteins Tet(M), Tet(O), TeTB(P), Tet(Q), and Tet(S), all specifying the tetracycline-minocycline resistance phenotype, were used to selectively amplify DNA fragments within the coding sequences. Nine streptococcal strains which do not carry the genes tet(M), tet(O), tetB(P), tet(Q), or tet(S) were investigated. Four of them gave no detectable PCR products. The five remaining strains each yielded a PCR product of 1.1 kbp. DNA hybridization experiments showed that these putative Tet determinants fell into four new hybridization classes, of which one, Tet T, was further analyzed. The gene tet(T) was isolated from Streptococcus pyogenes A498, and the nucleotide sequence that was necessary and sufficient for the expression of tetracycline resistance in Escherichia coli was determined. The deduced Tet(T) protein consists of 651 amino acids. The protein most closely related to Tet(T) was Tet(Q), which has 49% identical amino acid residues. A phylogenetic analysis revealed that Tet T represents a novel branching order among the Tet determinants so far described.

SUBMITTER: Clermont D

PROVIDER: S-EPMC163670 | biostudies-other | 1997 Jan

REPOSITORIES: biostudies-other

ACCESS DATA

Publications

New tetracycline resistance determinants coding for ribosomal protection in streptococci and nucleotide sequence of tet(T) isolated from Streptococcus pyogenes A498.

Clermont D D Chesneau O O De Cespédès G G Horaud T T

Antimicrobial agents and chemotherapy 19970101 1

An approach based on PCR has been developed to identify new members of the tet gene family in streptococci resistant to tetracycline and minocycline. Degenerate primers, corresponding to portions of the conserved domains of the proteins Tet(M), Tet(O), TeTB(P), Tet(Q), and Tet(S), all specifying the tetracycline-minocycline resistance phenotype, were used to selectively amplify DNA fragments within the coding sequences. Nine streptococcal strains which do not carry the genes tet(M), tet(O), tetB ...[more]

PMID: 8980765

Similar Datasets

Project description:This study was directed at characterizing the genetic elements carrying the methylase gene erm(B), encoding ribosome modification-mediated resistance to macrolide, lincosamide, and streptogramin B (MLS) antibiotics, in Streptococcus pyogenes. In this species, erm(B) is responsible for MLS resistance in constitutively resistant isolates (cMLS phenotype) and in a subset (iMLS-A) of inducibly resistant isolates. A total of 125 erm(B)-positive strains were investigated, 81 iMLS-A (uniformly tetracycline susceptible) and 44 cMLS (29 tetracycline resistant and 15 tetracycline susceptible). Whereas all tetracycline-resistant isolates carried the tet(M) gene, tet(M) sequences were also detected in most tetracycline-susceptible isolates (81/81 iMLS-A and 7/15 cMLS). In 2 of the 8 tet(M)-negative cMLS isolates, erm(B) was carried by a plasmid-located Tn917-like transposon. erm(B)- and tet(M)-positive isolates were tested by PCR for the presence of genes int (integrase), xis (excisase), and tndX (resolvase), associated with conjugative transposons of the Tn916 family. In mating experiments using representatives of different combinations of phenotypic and genotypic characteristics as donors, erm(B) and tet(M) were consistently cotransferred, suggesting their linkage in individual genetic elements. The linkage was confirmed by pulsed-field gel electrophoresis and hybridization studies, and different elements, variably associated with the different phenotypes/genotypes, were detected and characterized by amplification and sequencing experiments. A previously unreported genetic organization, observed in all iMLS-A and some cMLS isolates, featured an erm(B)-containing DNA insertion into the tet(M) gene of a defective Tn5397, a Tn916-related transposon. This new element was designated Tn1116. Genetic elements not previously described in S. pyogenes also included Tn6002, an unpublished transposon whose complete sequence is available in GenBank, and Tn3872, a composite element resulting from the insertion of the Tn917 transposon into Tn916 [associated with a tet(M) gene expressed in some cMLS isolates and silent in others]. The high frequency of association between a tetracycline-susceptible phenotype and tet(M) genes suggests that transposons of the Tn916 family, so far typically associated solely with a tetracycline-resistant phenotype, may be more widespread in S. pyogenes than currently believed.

Dataset Information

New tetracycline resistance determinants coding for ribosomal protection in streptococci and nucleotide sequence of tet(T) isolated from Streptococcus pyogenes A498.

Publications

New tetracycline resistance determinants coding for ribosomal protection in streptococci and nucleotide sequence of tet(T) isolated from Streptococcus pyogenes A498.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets