Imipenem Resistance in <i>Salmonella enterica</i> Serovar Wien Related to Porin Loss and CMY-4 β-Lactamase Production

Abstract

Two multidrug-resistant Salmonella enterica serovar Wien strains (SW468 and SW1107) were isolated in 2001 in Tunis. Both strains produced the beta-lactamases TEM-1, SHV-2a, and CMY-4, whereas strain SW1107 also produced the beta-lactamase CTX-M-3. The imipenem-resistant strain (SW468) was totally devoid of the OmpF-immunorelated porin. Imipenem resistance was shown as being related to porin loss and CMY-4 beta-lactamase production.