[Studies on characteristics of bacteria which cause infectious stone]

Culture of stones and electrical microscopic observation were performed with stones collected from forty-eight patients who underwent surgery for urolithiasis. Thirty-six strains of bacteria in the stones obtained form stone culture were classified as nineteen strains of bacteria deriving from primary infection stones (Group A-I) and seventeen strains of bacteria deriving from metabolic stones (Group A-M). As for their ability to produce urease and glycocalyx, they were studied in comparison with forty-nine strains of stone surface-adhering bacteria (Group B). Glycocalyx producing ability was examined by the provisional quantitative toluidine blue assay and safranine straining method. As for the electrical microscopic observation, formation of biofilm bacterium was observed in all twenty cases of primary infection stones and in thirteen cases (46.4%) of twenty-eight cases of metabolic stones. Urease producing ability per stone was 6/14 (43.9%) in Group A-I, 4/13 (30.8%) in Group A-M and, 4/32 (12.5%) in Group B. There was a significant difference (p < 0.05) between Group A-I and Group B. Similarly for the glycocalyx producing ratio (toluidine blue assay), the values were 9/14 (64.3%) in Group A-I, 11/3 (84.6%) in Group A-M and 10/32 (31.3%) in Group B. As for the glycocalyx producing ration (safranine method), the values were 10/14 (71.4%) in Group A-I, 9/13 (69.2%) in Group A-M and 9/32 (28.1%) in Group B. As for the glycocalyx producing ability, Group A-I and Group A-M both showed significantly higher production ratios compared to Group B for both toluidine blue method and safranine method.(ABSTRACT TRUNCATED AT 250 WORDS)