Temocillin is a semi-synthetic b-lactam antibiotic which is the 6-a-methoxy derivative of ticarcillin. It is a narrow-spectrum agent and its activity is almost exclusively limited to the Enterobacteriaceae—it is not effective against Gram-positive organisms, anaerobes or Pseudomonas aeruginosa. 1 As temocillin is highly stable against hydrolysis by b-lactamases, including extendedspectrum and AmpC b-lactamases, it provides a therapeutic option in the management of infections caused by multiresistant Enterobacteriaceae. The clinical efficacy of temocillin in this setting has recently been demonstrated. 2