Cefquinome (CQN)

Cefquinome is a fourth generation cephalosporin with pharmacological and antibacterial properties valuable in the treatment of coliform mastitis and other infections. It is only used in veterinary applications. Cefquinome is resistant to beta-lactamase. Chemically, its zwitterionic structure can facilitate rapid penetration across biological membranes, including porins of bacterial cell wall. Plus, it has a higher affinity to target penicillin binding proteins. The reactive site is a beta-lactam nucleus, while the main peripheral functional groups are a quaternary quinolinium, an aminothiazolyl moiety and an unusual O-alkylated oxime. Cefquinome acts by inhibition of the cell wall synthesis, but it has a relatively short half-life of about two and half hours. Cefquinome concentrations were calculated by regression analysis, using the standard curves in which logarithms of the concentration were proportional to the areas of the inhibition zones.