During B lymphocyte development, immunoglobulin heavy-chain variable (VH), diversity (DH), and joining (JH) segments assemble to generate a diverse antigen receptor repertoire. Here, we have marked the distal VH and DH-JH-Eμ regions with Tet-operator binding sites and traced their 3D trajectories in pro-B cells transduced with a retrovirus encoding Tet-repressor-EGFP. We found that these elemen...

A study of the interaction with calf thymus DNA is described of a novel set of chiral ternary complex cations of general form [Ru(N(4)-tet)(phdi)](2+) (where N(4)-tet is the chiral linear tetradentate R(*)R(*)-picchxn or R(*)-picchxnMe(2)). Individual equilibrium binding constants (K(B)) have been determined from spectroscopic titrations employing the hypochromism induced in the visible absorba...

Tigecycline is a glycylcycline antibiotic active against multidrug-resistant bacterial pathogens. The objectives of our study were to examine the potential of the Tet(A), Tet(K), Tet(M), and Tet(X) tetracycline resistance proteins to acquire mutations causing tigecycline resistance and to determine how this affects resistance to earlier classes of tetracyclines. Mutations in all four tet genes ...

Purpose: To determine the prevalence and genetic basis of tetracycline resistance in Staphylococcus aureus. Methods: One hundred and thirty (130) clinical isolates of S. aureus were collected from Khyber Teaching Hospital, Peshawar, Pakistan. Susceptibility to antibiotics (doxycycline, tetracycline and minocycline) was determined by Kirby-Bauer disc diffusion method with minimum inhibitory conc...

This study describes the use of the polymerase chain reaction (PCR) to detect the tet(K) and tet(M) tetracycline resistance genes in Staphylococcus aureus. Primers based on the DNA sequence of the tet(K) and tet(M) genes from S. aureus were used as primers in the PCR assay to detect the presence of genes for resistance to tetracycline and minocycline. Two-hundred and fifteen isolates of S. aure...

by the integration of a partly truncated class 2 integron as well as the deletion of large parts of the mobA gene (including the mobB gene) and the tetracycline resistance gene tet(B). To the best of our knowledge, this is the first description of class 2-associated resistance gene cassettes in members of the genus Pasteurella. In contrast to P. multocida, which is found in the respiratory trac...

Oxidative damage and inflammation are proposed to be involved in an age-related functional decline of exocrine glands. However, the molecular mechanism of how oxidative stress affects the secretory function of exocrine glands is unclear. We developed a novel mev-1 conditional transgenic mouse model (Tet-mev-1) using a modified tetracycline system (Tet-On/Off system). This mouse model demonstrat...

A basic understanding of abundance and diversity of antibiotic-resistant microbes and their genetic determinants is necessary for finding a way to prevent and control the spread of antibiotic resistance. For this purpose, chloramphenicol and multiple antibiotic-resistant bacteria were screened from a mariculture farm in northern China. Both sea cucumber and sea urchin rearing ponds were populat...

OBJECTIVES To investigate the distribution of, associations between and the transferability of antimicrobial resistance genes in resistant Escherichia coli strains isolated from Norwegian meat and meat products. METHODS The 241 strains investigated were collected within the frame of the Norwegian monitoring programme for antimicrobial resistance in bacteria from feed, food and animals (NORM-V...