[Activity of 14 antimicrobials against Eikenella corrodens]

Eikenella corrodens is a gram-negative bacillus that colonizes as normal flora of the mouth, the upper respiratory tract and the gastrointestinal tract. The aim of this study was to determine the susceptibility patterns against fourteen antibiotics of 25 E. corrodens strains isolated at our hospital. MICs were determined by the agar dilution technique using Müeller-Hinton agar with sheep blood (5% v/v) to penicillin, ampicillin, ampicillin-sulbactam, cephalotin, cefoxitin, ceftiaxone, colistin, gentamicin, amikacin, erythromycin, rifampin, ciprofloxacin and clindamycin. The most active antibiotics were ciprofloxacin and ceftriaxone (MIC90 = 0.008 and 0.125 microgram/ml, respectively), whereas eritromycin, gentamicin and amikacin showed less activity. Only one strain was beta lactamase positive, and it was inhibited by sulbactam. Erithromycin, gentamicin and amikacin had poor activity (MIC90 = 16.8 and 64 micrograms/ml, respectively), whereas all the strains were uniformly resistant to clindamycin (MIC > or = 32 micrograms/ml). We suggest about the need of periodical surveys of E. corrodens susceptibility patterns, since strains have been found with decreased susceptibility against antibiotics which are currently being used for the treatment of infectious diseases.