Glycylcyclines - Third generation tetracycline analogues

Emerging Electrochemical Sensors for Real-Time Detection of Tetracyclines in Milk

Antimicrobial drug residues in food are strictly controlled and monitored by national laws in most territories. Tetracyclines are a major broad-spectrum antibiotic class, active against a wide range of Gram-positive and Gram-negative bacteria, and they are the leading choice for the treatment of many conditions in veterinary medicine in recent years. In dairy farms, milk from cows being treated with antibiotic drugs, such as tetracyclines, is considered unfit for human consumption. Contamination of the farm bulk tank with milk containing these residues presents a threat to confidence of supply and results in financial losses to farmers and dairy. Real-time monitoring of milk production for antimicrobial residues could reduce this risk and help to minimise the release of residues into the environment where they can cause reservoirs of antimicrobial resistance. In this article, we review the existing literature for the detection of tetracyclines in cow's milk. Firstly, the complex nature of the milk matrix is described, and the test strategies in commercial use are outlined. Following this, emerging biosensors in the low-cost biosensors field are contrasted against each other, focusing upon electrochemical biosensors. Existing commercial tests that identify antimicrobial residues within milk are largely limited to beta-lactam detection, or non-specific detection of microbial inhibition, with tests specific to tetracycline residues less prevalent. Herein, we review a number of emerging electrochemical biosensor detection strategies for tetracyclines, which have the potential to close this gap and address the industry challenges associated with existing tests.

Protein synthesis as a target for antibacterial drugs: current status and future opportunities

The discovery and development of clinically useful antibiotic classes, such as the aminoglycosides, macrolides and tetracyclines, have clearly demonstrated that bacterial protein synthesis is a suitable target for drug intervention. New information on the binding of classical protein synthesis inhibitors to ribosomal RNA provides a rational explanation for their selective action against bacteria and also explains why chromosomal point mutations conferring resistance by structural changes at the target site are relatively rare in the majority of bacteria. These principles will be helpful when considering strategies for the screening or design of novel protein synthesis inhibitors that could be developed as new antibiotics. Recent progress in the discovery and development of bacterial protein synthesis inhibitors is illustrated by consideration of the glycylcyclines, ketolides, oxazolidinones and streptogramins.