A new method using a bacterium for dissolution of urinary stone

目的：氧化硫硫杆菌是一种细菌，它能将无机硫化物氧化成硫酸以获得生长所需的能量。方法：氧化硫硫杆菌(IFO编号18701)购自日本大阪Hakko Kenkyujyo Co.。在80℃的培养条件下，细菌培养7天。将培养基pH由4.82变为1.95，共培养28天。通过添加不同数量的硫代硫酸钠，还检测了人体尿液中细菌的生长情况。在Wistar大鼠膀胱中加入细菌(1×108)7d，观察人尿路结石的溶解情况。每日腹腔注射5%硫代硫酸钠20ml1次。同时进行尿路组织学检查和血常规检查。结果：人尿细菌数量随硫代硫酸钠浓度的增加而增加。在不同类型的尿路结石中，以大鼠膀胱干重减少78%的方式溶解的磷酸钙结石最多。草酸钙、尿酸和磷酸镁结石溶解不好。而对照组大鼠的结石重量增加了一倍。大鼠膀胱有轻度炎症反应。结论：氧化硫硫杆菌可用于尿路结石的溶解。这一新技术可能有助于ESWL和晶体覆盖的尿路支架术后碎片的溶解。

Purpose : A bacterium, Thiobacillus thiooxidans, oxidizes inorganic sulfur compounds to sulfuric acid to obtain energy for growth. We examined dissolution of urinary stones by the bacteria and studied optimal conditions for the dissolution in human urine.Methods : Thiobacillus thiooxidans (IFO No.18701) was purchased from Hakko Kenkyujyo, Co., Osaka, Japan. The bacteria were grown stationary for 7 days at 80℃ in medium. The pH of the medium was changed from pH 4.82 to 1.95 for 28 days. Growth of the bacteria was also examined in human urine by addition of different amounts of sodium thiosulfite. The dissolution of human urinary stones was examined in the bladder of Wistar rat containing the bacteria (1×10^8) for 7 days. A 20ml of 5% sodium thiosulfite was injected intraperitoneally once a day. Histological changes of urinary tracts and blood test were also examined. As a control, two rats were examined in the same methods without the bacteria.Results : The number of bacteria was increased in human urine depending the concentrations of sodium thiosulfite. Among different kinds of urinary stones, calcium phosphate stone was most dissolved by 78% reduction of dry weight in the rat bladder. Calcium oxalate, uric acid and magnesium phosphate stones were not well dissolved. But, the stone weight in the control rats were increased twice. Slight inflammation was found in the rat bladder. There were no abnormal findings in the blood test.Conclusions : Thiobacillus thiooxidans can be used for dissolution of urinary stones. This new technique may be useful for dissolution of fragments after ESWL and crystals covered urinary stent.