摘要目的 评价细菌超声分散计数仪在MTB药物敏感性试验(药敏试验)中的应用价值.方法 采用细菌超声分散计数仪和手工法磨菌分别对MTB进行分散和比浊,将调整至1.0麦氏浊度的菌悬液分别从镜检及菌落生长计数两方面验证细菌分散效果及细菌活性.收集2015年1-6月上海市各结核病定点医院新诊断的肺结核患者痰标本中分离培养获得的MTB临床菌株726株,分别采用手工磨菌和仪器超声分散细菌2种方法制备MTB菌悬液,进行一线抗结核药物比例法药敏试验,37 ℃温箱中培养28 d后,观察并比较2种不同方法制备的菌悬液比例法的药敏试验结果.2种磨菌方法接种的不同浓度对照培养基上菌落生长情况的比较采用配对卡方检验,P<0.05表示差异有统计学意义.结果 采用2种磨菌方法分别对726株MTB临床菌株菌悬液进行的药敏试验(比例法)结果均相同.2种磨菌方法接种的高浓度对照培养基上菌落生长情况比较差异有统计学意义(χ2=8.0,P<0.01),细菌超声分散计数仪法在低浓度对照培养基上的菌落可数率达到97.7%,手工磨菌法可数率仅为4.3%,2种磨菌方法接种的低浓度对照培养基上菌落生长情况比较差异有统计学意义(χ2=674,P<0.001).结论 细菌超声分散计数仪制备的菌悬液进行MTB药敏试验时,低浓度对照管菌落数量可数性好,高低浓度对照管菌落数对比明显,更利于对药敏试验结果的科学判读.用细菌超声分散计数仪进行MTB药敏试验(比例法),可增加试验操作的自动化,结果更具有客观性和可比性,可减少试验中的人为误差.与传统手工磨菌法比较,细菌超声分散计数仪不影响细菌活力,对MTB分散效果更好.

abstractsObjective To evaluate the application of the BACspreaderTM Microbe Dispersion Counter in drug susceptibility test (DST) on Mycobacterium tuberculosis (MTB).Methods The MTB strains were dispersed and diluted to 1.0 McFarland standard turbidity,by means of BACspreaderTM Microbe Dispersion Counter and manual grinding method,respectively.The bacterial dispersion effect and bacterial activity were tested by microscope and colony counting method.During Jan.2015 to June 2015,a total of 726 isolates of MTB were collected in all district tuberculosis hospitals of Shanghai.The bacterial suspension dispersed by instrument and manual grinding,were inoculated in slant medium for DST (Proportion Method),and then incubated in 37 ℃ incubator for 28 days and the DST results were reported.The effects of the 2 different bacterial dispersion methods were compared by comparing DST results and counting the bacterial colony which grew in high and low concentration control media.Paired chi-square test was used for statistical analysis,and the significance level was 0.05.Results Compared to the manual grinding method,the MTB colony could be better dispersed by BACspreaderTM Microbe Dispersion Counter,without reducing the bacterial activity.The DST results of 726 mycobacterial isolates were the same by different bacterial dispersion methods.The count of bacterial colony growing in high concentration control medium was significantly different between of the 2 dispersion methods (χ2=8.0,P<0.01).When counting the bacterial colony growing in low concentration control medium,the numerable rate was 97.7% by BACspreaderTM Microbe Dispersion Counter,and 4.3% by manual grinding method;the difference being significant between the 2 dispersion methods (χ2=674,P<0.001).Conclusions Compared to the manual grinding method,the slant medium inoculated with bacterial suspension obtained by BACspreaderTM Microbe Dispersion Counter had better countability in low concentration control slants,and had more significant contrast between high and low concentration control slants,which was useful to determine the DST results.Introducing the BACspreaderTM Microbe Dispersion Counter to MTB DST could automate the DST process,make the testing results objective and standardized,and reduce personal error in the tests..