A new method using a bacterium for dissolution of urinary stone

目的：一种细菌，硫氧化硫杆菌，将无机硫化合物氧化成硫酸，以获得生长所需的能量。我们研究了细菌对尿路结石的溶解作用，并研究了在人尿中溶解的最佳条件。方法：硫氧化硫杆菌（IFO No.18701）购自日本大阪Hakko Kenkyujyo公司。细菌在80℃培养基中静止生长7天。培养基的pH由4.82变为1.95，持续28 d。通过添加不同量的硫代亚硫酸钠，研究了人类尿液中细菌的生长情况。在含有细菌（1×10^8）的Wistar大鼠膀胱中观察7天人类尿路结石的溶解情况。腹腔注射5%硫代亚硫酸钠20ml，每天1次。同时检查尿路组织学变化及血液检查。作为对照，用同样的方法检查了两只没有细菌的大鼠。结果：人尿细菌数量随亚硫酸钠浓度的增加而增加。在不同种类的尿结石中，磷酸钙结石溶解最多，使大鼠膀胱干重减轻78%。草酸钙、尿酸、磷酸镁结石溶解不良。对照组大鼠的体重增加了2倍。在大鼠膀胱中发现轻微炎症。验血没有发现异常。结论：硫氧化硫杆菌可用于尿路结石的溶出。这项新技术可用于体外冲击波碎石后碎片的溶解和尿路支架覆盖晶体的溶解。

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.