Identification of ‘Campylobacter upsaliensis’ and other catalase-negative campylobacters from paediatric blood cultures by numerical analysis of electrophoretic protein patterns

Twenty-one strains of catalase-negative campylobacters from paediatric blood cultures were characterized by one-dimensional SDS-PAGE of cellular proteins. A further 11 Campylobacter strains were included for reference purposes. The partial protein patterns were used as the basis of a numerical analysis, which showed that 17 hippurate-negative strains had a high similarity to ‘ C. upsaliensis ’ ( r ⩾ 0.82) irrespective of their geographical location, and that three hippurate-positive isolates had a high similarity ( r ⩾ 0.87) to C. jejuni subsp. jejuni . One hippurate-positive CNW strain was not identified. The analysis of SDS-PAGE protein patterns proved an excellent method of characterizing these thermophilic campylobacter as they were difficult to identify by traditional methods.