临床分枝杆菌培养中同步筛检依赖利福平菌的应用价值探讨

目的 探讨分枝杆菌培养中同步筛检依赖利福平结核分枝杆菌（依R菌）的临床应用价值，以期为临床依R菌早期发现提供帮助。 方法 采用临床典型依R菌株在罗氏（L-J）培养基上的最佳生长利福平药物浓度100μg/ml（简称“L-J R100”），建立临床依R菌初代筛检模式，即在临床分枝杆菌BD960快速分离培养中，平行接种L-J R100 管和罗氏空白对照管（L-J对照）培养；按照其模式对重庆市公共卫生医疗救治中心2011年3月7日至2012年2月15日期间共5362份临床标本平行培养结果进行统计分析（实验结果录入瑞美检验网络LIS系统）。 结果BD960、L-J R100和L-J对照管3种方法平行培养的总阳性检出率为43.92% (2355株/5362份)，其中BD960阳性检出率39.56%（2121株/5362份），L-J对照管阳性检出率25.57%（1371株/5362份）。BD960阴性但L-J对照管培养阳性者234份；L-J R100阳性703株，占检出阳性的29.85%(703株/2355株）；发现有依R菌现象的258株（合计221例，其中重复出现依R菌现象2次的33例、3次的1例、4次的3例，另外有14株L-J R100阳性而对照为阴性的绝对依赖株），占L-J对照管阳性的18.82%（258株/1371株），占L-J R100阳性的36.70%（258株/703株）。 结论 临床分枝杆菌培养中同步筛检依R菌能分离到绝对依赖株，可提早为临床提示分离阳性株是否为利福平依赖菌或耐药菌；同时可提高分枝杆菌培养阳性检出率；其方法简单易行，有较好的临床应用价值。

Research on synchronously screening the rifampin-dependent M.tuberculosis during Mycobacterium culture

Objective To study practical value of synchronously screening the rifampin-dependent（R-dependent） M.tuberculosis（Mtb） strains during routine Mycobacterium culture,to early diagnose R-dependent infec-tion in a clinical setting.Methods Based on the typical growth conditions for R-dependent strains from clinical specimens in Lowenstein-Jensen medium（L-J） which contained rifampicin at concentration of 100 μg/ml（L-J R100）,a primary screening model was established.In routine BD960 fast liquid culture process,clinical specimens were also simultaneously inoculated in L-J culture medium without and with rifampin（L-J R100）.A R-resistant Mtb is defined as culture-positive bacterium which grew better in L-J R100 than that in L-J（R-dependent）,and an absolute R-dependent Mtb is defined as positive culture only in L-J R100 but negative culture in L-J.A total of 5362 specimens were examined during the period of March 7,2011 to February,15,2012 in Chongqing Public Health Medical Center,and results were analyzed with LIS software system（Ruimei,Shanghai,China）.Results Of 5362 cases,the total positive rate of the combined three methods of BD960,L-J and L-J R100 was 43.92%（2355/5362）,the positive rates of BD960 and L-J culture were 39.56%（2121/5362） and 25.57%（1371/5362） respectively.234 specimens were L-J positive and BD960 negative.Of 2355 culture-positive specimens,703（29.85%,703/2355） were L-J R100 positive,in which 258 isolates from 221 cases were R-dependent and 14 isolates were absolute R-dependent.The R-dependent phenomenon was also observed repeatedly twice in 33 isolates,3 times in 1 isolate and 4 times in 3 isolates.Conclusion The synchronously screening the rifampin-dependent Mtb strains during routine Mycobacterium culture is a simple method for early diagnosing the TB patients infected by the rifampin-dependent or rifampin-resistant strains of M.tuberculosis.It also improves the positive rate of Mycobacterium culture.