Enterococcal gap

Term indicating that cephalosporins have no effect against enterococci and listeria.

Cephalosporins are β-lactam antibiotics that have a bactericidal effect by inhibiting the synthesis of the cell wall. Cephalosporins of the 1st generation (cefazolin) are mainly effective in the gram-positive range. With their further development (2nd generation: cefuroxime, 3rd generation: ceftriaxone (3a), ceftazidime (3b), 4th generation: cefepim, 5th generation: ceftarolin) the spectrum of activity has been extended into the gram negative range.

Cephalosporins bind to bacteria via structural proteins, the penicillin binding proteins, PBP. In Listeria monocytogenes the essential penicillin binding protein3, PBP3 and in all Enterococci the penicillin binding protein5, PBP5 is altered, so that cephalosporins are no longer effective.