Abstract: Corynebacterium striatum is a nosocomial opportunistic pathogen increasingly associated with a wide
range of human infections and is often resistant to several antibiotics. We investigated the susceptibility
of 63 C. striatum isolated at the Farhat-Hached hospital, Sousse (Tunisia), during the period 2011?2014,
to a panel of 16 compounds belonging to the main clinically relevant classes of antimicrobial agents.
All strains were susceptible to vancomycin, linezolid, and daptomycin. Amikacin and gentamicin
also showed good activity (MICs90 = 1 and 2 mg/L, respectively). High rates of resistance to penicillin
(82.5%), clindamycin (79.4%), cefotaxime (60.3%), erythromycin (47.6%), ciprofloxacin (36.5%),
moxifloxacin (34.9%), and rifampicin (25.4%) were observed. Fifty-nine (93.7%) out of the 63 isolates
showed resistance to at least one compound and 31 (49.2%) were multidrug-resistant. Twenty-nine
resistance profiles were distinguished among the 59 resistant C. striatum. Most of the strains resistant
to fluoroquinolones showed a double mutation leading to an amino acid change in positions 87 and 91 in
the quinolone resistance-determining region of the gyrA gene. The 52 strains resistant to penicillin were
positive for the gene bla, encoding a class A ?-lactamase. Twenty-two PFGE patterns were identified
among the 63 C. striatum, indicating that some clones have spread within the hospital.