Ribosome protection proteins (RPPs) confer tetracycline resistance by binding to the ribosome and chasing the drug from its binding site. The current model for the mechanism of action of RPPs proposes that drug release is indirect and achieved via conformational changes within the drug-binding site induced upon binding of the RPP to the ribosome. Here we report a cryo-EM structure of the RPP Te...

High frequency transfer and elimination of drug resistance may indicate an extrachromosomal inheritance of genetic determinants. This study shows the cure and transfer of a small plasmid and tetracycline resistance in Staphylococcus aureus 1030 (55)Tet strains. Several methods are available for plasmid elimination. We used ethidium bromide, an agent that binds to DNA, and thus inhibits DNA poly...

Many strains of Chlamydia suis, a pathogen of pigs, express a stable tetracycline resistance phenotype. We demonstrate that this resistance pattern is associated with a resistance gene, tet(C), in the chlamydial chromosome. Four related genomic islands were identified in seven tetracycline-resistant C. suis strains. All resistant isolates carry the structural gene tet(C) and the tetracycline re...

We show that for two well-characterized regulatory circuits in Escherichia coli, Tn10 tetracycline resistance and porin osmoregulation, the transcriptional outputs in individual cells are graded functions of the applied stimuli. These systems are therefore examples of naturally occurring regulatory circuits that exhibit continuous control of transcription. Surprisingly, however, we find that po...

Mosaic tetracycline resistance genes comprising tet(O), tet(W), and tet(32) sequences were abundant in DNA extracted from pig and human fecal samples, accounting for 78% (50/64) and 46% (37/80) of genes amplified with a tet(O) primer set, respectively, in two samples. The nonmosaic tet(32) gene was isolated from a human saliva bacterium.

The ecological impact of antibiotic resistance in the absence of selective pressure has been poorly studied. We assessed the carriage of tetracycline resistance genes, persistence in the microbiota, fecal population counts and virulence factor genes in 309 commensal, intestinal Escherichia coli strains obtained from 128 Swedish infants followed during the first year of life with regular quantit...

We studied antimicrobial-resistant Klebsiella pneumoniae for 1998-2010 by using data from The Surveillance Network. Susceptibility results (n = 3,132,354) demonstrated significant increases in resistance to all antimicrobial drugs studied, except tetracycline. Cross-resistance among carbapenem-resistant K. pneumoniae was lower for tetracycline and amikacin.

Antibiotic pollution has recently been a global environmental and human health concern. When bacteria are exposed to antibiotics, they express drug resistance. Drug resistance genes can be vertically and horizontally transferred in the environment. In this paper, I provide a summary of our work on one category of tetracycline resistance gene, termed ribosomal protection protein gene. In particu...

One S. aureus plasmid coding for tetracycline resistance, pT127, and four plasmids (pC194, pC221, pC223, and pUB112) coding for chloramphenicol resistance have been introduced by transformation into B, subtilis. The plasmids replicate in--and confer antibiotic resistance upon--their new host. These experiments show that the potential for genetic exchange between diverse bacterial species is gre...