Isolation of Eikenella corrodens in a general hospital

Eikenella corrodens is a small pleomorphic gram-negative bacillus which produces pitting on agar. From December 19, 1970, to December 2, 1971, E. corrodens (also known as HBI) was isolated from material submitted to the Diagnostic Bacteriology Laboratory of the Boston City Hospital from 72 patients (48 males, 24 females) ranging in age from 8 months to 92 years. The organism was recovered from sputum or bronchial washings in 46 instances, from throat or nasopharyngeal swabs in 11, from wounds in 8, from 2 human bites, and from 3 abscesses. It was isolated in pure culture from one of the human bites. Antibiotic susceptibility was measured for 26 strains against six antibiotics by using the inocula replicating method on heart infusion blood agar. E. corrodens was most susceptible to penicillin and ampicillin with 100% and 96% of strains inhibited by 1.65 mug of these antibiotics per ml, respectively. Eighty percent of the strains were inhibited by 3.125 mug of chloramphenicol per ml and 52% were inhibited by this amount of gentamicin. Resistance was greater for tetracycline and clindamycin.