Analysis Of Predominant Serotypes Of E.coli In Bile Of Patients With Pigment Stones And Comparison Of β-Glucuronidase Activity Produced By Each

Objective:The activity ofβ-glucuronidase produced by E.coli subtypes in bile duct bile of patients with pigment stones was compared,and then the predominant serotype of E.coli that caused the formation of pigment stones was explored.Method:A total of 70 patients with common bile duct stones were treated with bile for bacterial culture,and the slide coagulation method was used to identify the serotypes of E.coli cultured in the bile.According to the activity ofβ-glucuronidase andβ-glucuronidase reaction with the substrate PNPG（4-nitrobenzene-β-D-glucoside）is directly proportional to the rate of k,inversely proportional to the OD600 value of the reaction system,we can calculateβ-glucuronidase activity of E.coli subtypes.Result:A total of 70 cases of bile duct bile specimens were obtained,and 61cases were positive for bacterial culture.The positive rate was 87.14%.Two or more kind of bacteria were isolated from 12 specimens,and a total of 73 strains were obtained.The culture results ranked first for Escherichia coli（34.25%）.The serotypes of the 25 strains of E.coli cultured were identified.A total of 13 E.coli serotypes were obtained,the top three being O₃₀,O₂₄,and O₇₉.;O₂₄4 serotypes E.coli have significantly higher time-slope k values than other serotypes.Combined with their OD600 values,it can be concluded that theirβ-glucuronidase activity is higher.Conclusion:The most common bacteria in the biliary tract of patients with pigment stones are E.coli,and the serotypes are mainly O30,O24 and O79.Among them,O₂₄4 serotype E.coli produceβ-glucuronidase activity.