改良离心集菌法检测痰内抗酸杆菌的研究

目的研究改良离心集菌法，测定其是否能使抗酸杆菌的诊断更为安全简便。方法选取传统的抗酸杆菌直接涂片法1＋和1＋以下的阳性标本100例，用改良离心集菌法复检；再配制浓度为10000、5000、1000和100条／mL的痰菌液各100份，分别用直接涂片法和改良离心集菌法检测其检出限和检出率；最后以日常门诊标本1036例分别用两种方法进行临床应用检测和分析。结果100例直接涂片法1＋和1＋以下的阳性标本改为改良离心集菌法复检，结果为4＋有93例、3＋为7例；直接涂片法和改良集菌法的检出限分别为1000和100条／mL；10000、5000、1000和100条／mL的痰菌液用直接涂片法和改良离心集菌法检测其检出率分别为97％、53％、5％、0％和100％、100％、94％、7％。1036例日常标本用直接涂片法和改良集菌法检测的阳性率分别12．74％和16．47％。结论改良离心集菌法的阳性率高于直接涂片法，检出限低于直接涂片法，不但大大改善了实验室和实验人员生物安全，还弥补了直接涂片法中对结核杆菌在痰液中分布不均一性带来的漏检的方法局限性，因此改良离心集菌法是安全、简便的抗酸杆菌实验室值得推广使用的新诊断方法。

Modified centrifuging and collecting method for detecting acid-fast bacilli in sputa

Objective To investigate the effect of modified centrifuging and collecting method for diagnosis of acid-fast bacilli.Methods 100 positive sputa samples(1+ or <1+) of acid-fast bacilli were detected by direct smear method(DSM) at first and then checked by modified centrifuging and collecting method(MCCM) again.In addition,100 samples with the concentrations of 10,000 bacteria/mL,5,000 bacteria/mL,1,000 bacteria/mL and 100 bacteria/mL,respectively,were used to identify the detectable limit and detectable rate by DSM and MCCM.Moreover,1,063 routine samples isolated from out-patients were detected by DSM and MCCM.Results In the 100 positive sputa samples(1+ or <1+),4+(93 samples) and 3+(7 samples) were detected by MCCM.The detectable limits were 1,000 bacteria/mL and 100 bacteria/mL,by DSM and MCCM respectively.The detectable rates of 10,000 bacteria/mL,5,000 bacteria/mL,1,000 bacteria/mL and 100 bacteria/mL were 97%,53%,5% and 0% by DSM,and 100%,100%,94% and 7%,by MCCM.The positive rates of the 1,036 routine samples were 12.74% and 16.47% by DSM and MCCM respectively.There was statistically significant difference between the 2 methods.Conclusion The positive rate of MCCM was higher than that of DSM,and the detectable limit of MCCM was lower than that of DSM.In addition,MCCM improves biological safety of laboratory and staffs,and remedies the drawbacks of DSM resulted from the heterogeneous distribution of the bacteria in sputa samples.Thus,MCCM is a recommendable,safe,easy-to-use method for the diagnosis of acid-fast bacilli.