What is tetracycline resistance gene?

Resistance to tetracycline is governed by tet genes, which are involved in either active efflux of the drug, ribosomal protection or enzymatic drug modification. 4. Among the various tet genes, the tet(A), tet(B), tet(D), tet(E) and tet(G) are reported in gram-negative bacteria.

How does tetracycline resistance gene work?

Resistance to tetracyclines is usually attributed to one or more of the following: the acquisition of mobile genetic elements carrying tetracycline-specific resistance genes, mutations within the ribosomal binding site, and/or chromosomal mutations leading to increased expression of intrinsic resistance mechanisms.

Do plasmids carry genes for antibiotic resistance?

Antibiotic resistance genes were not common on plasmids before the introduction of antibiotics as medicines. Today, however, genes that provide protection against different antibiotics as well as resistance to for example heavy metals like copper and silver are commonly found on the same plasmids.

Why would a plasmid have a gene for Tet resistance?

Adding an antibiotic resistance gene to the plasmid solves both problems at once – it allows a scientist to easily detect plasmid-containing bacteria when the cells are grown on selective media, and provides those bacteria with a pressure to keep your plasmid.

What does tetracycline do to E coli?

Tetracycline exerts its antibacterial action by binding to the bacterial ribosome and inhibiting protein synthesis (30). It is one of the earliest broad-spectrum antimicrobials, and since it was developed in the 1940s, it has been produced at the largest scale of all antibiotics (28).

Can drug resistance be carried on a plasmid?

The plasmids can be transferred between bacteria within the same species or between different species via conjugation. Plasmids often carry multiple antibiotic resistance genes, contributing to the spread of multidrug-resistance (MDR).

Why is E. coli sensitive to tetracycline?

coli (4, 7), which suggests that resistance has been selected by a bystander effect on commensal E. coli, during treatment of other pathogens in humans or animals. Bacterial resistance to tetracycline is most commonly mediated by energy-dependent pumping of tetracycline out of the bacterial cell.

Which plasmid is responsible for antibiotic resistance in E. coli?

F Plasmids Are the Major Carriers of Antibiotic Resistance Genes in Human-Associated Commensal Escherichia coli.

Are there genes that protect the ribosome from tetracycline?

Resistance genes such as tetM and others (see Table 18-6) protect the ribosome from tetracycline action.

How is tetracycline resistance acquired in Gram positive organisms?

In gram-positive organisms, resistance to tetracycline is typically conferred by ribosome protection genes, such as tet (M) and tet (O). Tetracycline resistance is usually acquired by GAS through horizontal gene transfer. A global sample of GAS revealed 80 or more separate acquisitions of tetracycline resistance.

How is tetracycline resistance caused by elongation factor G?

Acquired tetracycline resistance can result from production of elongation-factor G (EF-G)-like ribosomal protection proteins that interact with the ribosome so that protein synthesis is unaffected by the presence of the antibiotic.

Is the mechanism of ribosomal protection similar to tetM?

Most of the work on the mechanism of ribosomal protection has been done on TetM. The ribosomal protection proteins encoded by the other classes have an amino acid sequence similarity of at least 40% to TetM. Therefore, the mechanism of action may be similar for all ribosomal protection proteins.

What is tetracycline resistance gene? Resistance to tetracycline is governed by tet genes, which are involved in either active efflux of the drug, ribosomal protection or enzymatic drug modification. 4. Among the various tet genes, the tet(A), tet(B), tet(D), tet(E) and tet(G) are reported in gram-negative bacteria. How does tetracycline resistance gene work? Resistance to…