Biochemical, antimicrobial susceptibility and genotyping studies on Corynebacterium urealyticum isolates from diverse sources

Thirty-two isolates of Corynebacterium urealyticum, isolated between 1991 a nd 1995, were studied by biochemical tests, phospholipid content, analysis of fatty and mycolic acids, ribotyping, whole-cell protein patterns and ant imicrobial susceptibility to six antibiotics. Nineteen isolates were from h uman and human-related sources (HHRS); the remainder were from animal and a nimal-related sources (AARS), Most C. urealyticum isolates were similar in their biochemical and whole-cell protein profiles, although most HHRS isola tes were alkaline phosphatase-positive (84%) and produced almost identical protein patterns, whereas AARS isolates were quite diverse. The qualitative composition of cellular fatty acids was identical for all isolates examine d. Twelve different ribotypes were obtained with HindIII producing four-to- seven bands. Ribotypes 8, 9 and 10 were predominant in isolates from HHRS, whereas in isolates from AARS, ribotypes 5 and 6 predominated. AARS isolate s were significantly less antibiotic-resistant, in comparison with HHRS iso lates, Ribotyping appeared to be the most useful tool for strain characteri sation.