Tet 42, a Novel Tetracycline Resistance Determinant Isolated from Deep Terrestrial Subsurface Bacteria

Brown, Mindy G.; Mitchell, Elizabeth; Balkwill, David L.

doi:10.1128/aac.00640-08

Cited by 23 publications

(10 citation statements)

References 23 publications

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“…The other Group-6 member is OtrC, a predicted ABC transporter from the oxytetracycline producer Streptomyces rimosus. The determinants discovered since these classifications were examined for their similarity to other tetracycline resistance elements using the antibiotic resistance gene (39) [21], Tet(41) [22], and Tet(42) [23] showed high similarity among themselves and to Tet(C) and so can be added to Group-1, whereas Tet(40) [24] with 43.4% average similarity to TetA(P) is placed in Group-4. Tet (38) [25] is another 14 TMS protein.…”

Section: Tetracycline Effluxmentioning

confidence: 99%

The tetracycline resistome

Thaker

Spanogiannopoulos

Wright

2009

Cell. Mol. Life Sci.

291

244

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Resistance to tetracycline emerged soon after its discovery six decades ago. Extensive clinical and non-clinical uses of this class of antibiotic over the years have combined to select for a large number of resistant determinants, collectively termed the tetracycline resistome. In order to impart resistance, microbes use different molecular mechanisms including target protection, active efflux, and enzymatic degradation. A deeper understanding of the structure, mechanism, and regulation of the genes and proteins associated with tetracycline resistance will contribute to the development of tetracycline derivatives that overcome resistance. Newer generations of tetracyclines derived from engineering of biosynthetic genetic programs, semi-synthesis, and in particular recent developments in their chemical synthesis, together with a growing understanding of resistance, will serve to retain this class of antibiotic to combat pathogens.

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Section: Tetracycline Effluxmentioning

confidence: 99%

The tetracycline resistome

Thaker

Spanogiannopoulos

Wright

2009

Cell. Mol. Life Sci.

291

244

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“…The majority of TCs are excreted into the environment via various pathways (e.g., agricultural runoff), and there is potential for resistance selection among pathogens and nonpathogens (8,14). To date, more than 40 classes of tetracycline resistance (tet) genes have been described in various environments (15,16), which encode three main resistance mechanisms (efflux pump proteins, ribosomal protection proteins (RPPs), and inactivating enzymes) (16). In China, tetracycline-resistant bacteria (e.g., Escherichia coli) and tet genes have been found in different water environments (12,13).…”

Section: Introductionmentioning

confidence: 99%

Abundance and Diversity of Tetracycline Resistance Genes in Soils Adjacent to Representative Swine Feedlots in China

Qiao

Zhang

et al. 2010

Environ. Sci. Technol.

319

152

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Tetracyclines are commonly used antibiotics in the swine industry for disease treatment and growth promotion. Tetracycline resistance was determined in soils sampled from farmlands in the vicinity of nine swine farms located in three cities in China. Totally, 15 tetracycline resistance (tet) genes were commonly detected in soil samples, including seven efflux pump genes (tetA, tetC, tetE, tetG, tetK, tetL, tetA/P), seven ribosomal protection proteins (RPPs) genes (tetM, tetO, tetQ, tetS, tetT, tetW, tetB/ P), and one enzymatic modification gene (tetX). The quantitative real-time PCR was further used to quantify five RPPs genes (tetM, tetO, tetQ, tetW, tetT) and 16S rRNA gene abundances. The concentrations of total tetracyclines (5 typical tetracyclines and 10 of their degradation products) in these soils were measured using liquid chromatography-electrospray tandem mass spectrometry (LC-MS/MS) and were found to range from 5.4 to 377.8 µg · kg -1 dry soil. Bivariate correlation analysis confirmed that absolute tet gene copies (sum of tetM, tetO, tetQ, tetW genes) were strongly correlated with the concentrations of tetracycline residues (r 2 ) 0.45, P < 0.05), ambient bacterial 16S-rRNA gene copies in each soil sample (r 2 ) 0.65, P < 0.01), and organic matter in soil (r 2 ) 0.46, P < 0.05), respectively. Finally, the phylogenetic analysis on tetM combined with cultureindependent molecular techniques revealed at least five genotypes of tetM in nine soil samples.

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“…In the case of TetR, the ␣ 8-␣ 9 loop seemed the most promising region to this end. Among the 15 different naturally occurring TetR orthologues known to date [Agersø and Guardabassi, 2005;Berens and Hillen, 2004;Brown et al, 2008;Thompson et al, 2007], little primary sequence conservation is observed within the loop, which is 12 to 21 amino acids long. This also holds true for the unique loops of the TetR variants described here.…”

Section: Discussionmentioning

confidence: 99%

In vivo Activation of Tetracycline Rep ressor by Cre/<i>lox</i>-Mediated Gene Assembly

Bertram

Kolb²,

Hillen³

2009

Microb Physiol

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Tetracycline repressor (TetR) bears an unstructured loop region between helices α8 and α9, which is moderately permissive to amino acid exchanges and length variations. Recognition sites for the site-specific recombinases Flp (FRT) or Cre (lox) were inserted in-frame into tetR, substituting some of this loop’s codons. A number of the deduced TetR variants displayed efficient regulation in vivo, thus allowing the establishment of a new mode of TetR activation on the genetic level. Chromosomally encoded tetR in Bacillus subtilis was disrupted and inactivated by insertion of a lox66-aphAIII-lox71 kanamycin resistance cassette. Marker excision by Cre recombinase led to the assembly of a novel tetR allele. The encoded regulator, termed TetR^lox72/1, is distinguished from wt-TetR by a slightly elongated and altered α8–α9 loop only, harboring an amino acid stretch encoded by lox72. Despite decreased intracellular protein amounts, TetR^lox72/1 displayed efficient in vivo activity in B. subtilis and E. coli, indistinguishable from that of wt-TetR. These results underline the sequence flexibility of TetR in the α8-α9 loop and demonstrate the possible use of the regulator as a read-out tool for the activity of site-specific recombinases.

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Tet 42, a Novel Tetracycline Resistance Determinant Isolated from Deep Terrestrial Subsurface Bacteria

Cited by 23 publications

References 23 publications

The tetracycline resistome

The tetracycline resistome

Abundance and Diversity of Tetracycline Resistance Genes in Soils Adjacent to Representative Swine Feedlots in China

In vivo Activation of Tetracycline Rep ressor by Cre/<i>lox</i>-Mediated Gene Assembly

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