Sutterella wadsworthensis is a newly described gram negative, asaccharolytic, microaerophilic rod that can be confused with Campylobacter gracilis. The description of S. wadsworthensis was based on 20 strains isolated from appendix tissue, peritoneal or abdominal fluid; C. gracilis strains were isolated from infections above the diaphragm with the exception of one strain from appendix tissue (Wexler et al., IJSB, 1996, 46:252). Inspection of data for additional S. wadsworthensis strains (46) indicates that 42 (88%) were isolated from abdominal sources with one strain each (2%) isolated from blood, brain abscess, joint fluld, leg wound and buttock abscess specimens. Sources of C. gracilis (17) included strains from abdominal specimens (7,41%), neck, chest, lung specimens (5,29%), other abscesses (3,18%), and blood (1,6%). In vitro activity was determined using the NCCLS-approved Wadsworth brucella laked blood agar diluation method. Antimicrobial agents (with susceptible [resistant] category breakpoints) included amoxicillin/clavulanate (2:1) (AC) and meropenem (Mer), 4 [16] µg/ml; cefoxibn (Fox) and ceftriaxone (Trx), 16 [64] l~g/ml; cefbzoxime (Zox), piperacillin (Pip), piperacillin/tazobactam (PT) and ticarcillin/clavulanate (TC), 32 [128] µg/ml; metronidazole (Met), 8 [32] µg/ml; and clindamycin (CC), 2 [8] µg/ml. All C. gracilis strains (10) were susceptible to every agent; MIC₉₀ values were <1 µ/ml for every antimicrobial agent except Fox, Pip, and PT. All S. wadsworthensis strains (19) were susceptible to AC, Fox, Trx, Mer, and TC. Other data for S. wadsworthensis:

Agent	MIC90(µg/ml)		% Susc., % Int., % Res

The data indicate that isolation of C. gracilis may not be limited to "above the diaphragm" whereas S. wadsworthensis may be only occasionally isolated from non-abdominal specimens. Identification of these isolates is important because of the antimicrobial resistance of S. wadsworthensis.