上海市某结核病定点医院结核病房空气样本中分枝杆菌的检测

Detection of M y cobacterium in the air of wards for tuberculosis patients from tuberculosis hospital in Shanghai

目的了解上海市某结核病定点医院结核病房空气中的分枝杆菌污染情况及潜在传染性。方法采用液体撞击式微生物气溶胶采样器(FA-1型撞击式空气微生物采样器)采集该医院22间结核病房中空气样本134份,均在痰涂片抗酸杆菌阳性(+～++++)患者床边采集。每间病房均有4张床位,每间病房的空间布局相同,但患者组成情况不完全相同。经氢氧化钠-N-乙酰-L-半胱氨酸(NALC-NaOH)前处理,分别采用罗氏培养、BacT/ALERT 3D全自动快速培养进行分枝杆菌分离培养,并对培养阳性样本采用DNA序列分析的方法进行菌型鉴定。两种分离培养方法对医院空气样本中分枝杆菌分离率的比较采用配对卡方检验,以P<0.05为差异有统计学意义。结果134份结核病房涂阳患者床边采集到的空气样本中有3份分枝杆菌分离培养阳性,经DNA序列分析证实分别为结核分枝杆菌、胞内分枝杆菌和戈登分枝杆菌。BacT/ALERT 3D培养阳性3份,经DNA序列分析证实分别为结核分枝杆菌、胞内分枝杆菌和戈登分枝杆菌,污染2份,阳性检出率为2.3%(3/132)。罗氏培养阳性2份,经DNA序列分析证实分别为胞内分枝杆菌和戈登分枝杆菌,污染1份,阳性检出率为1.5%(2/133)。经配对卡方检验,两种分离培养方法对医院空气样本中分枝杆菌分离率差异无统计学意义(χ2=0.00,P>0.05)。结论该医院结核病房痰涂片抗酸杆菌阳性患者床边所采集的空气样本中可分离到分枝杆菌,虽然目前尚无法判断这些菌株是否由于就诊患者传播所致,但是定期监测医院内空气质量是预防与控制医院内感染的一项重要措施。

Objective To assess the risk of aerosol transmission of Mycobacterium in the air of the wards of tuberculosis （TB） inpatient in TB hospital. Methods 134 air samples were collected from the air of 22 wards housing sputum smear-positive patients in TB hospital by using the microbial aerosols liquid percussive sampler （FA-1 type air sampler）. The air samples were digested and depolluted by NALC-NaOH, then inoculated in L-J culture medium and BacT/ALERT 3D culture system, respectively. The culture-recovery samples were identified by Ziehl-Neelsen staining and DNA sequencing. The Mycobacterium culture-recovery rates of L-J culture and BacT/ALERT 3D culture were compared and statistically analyzed using chi-square test of paired comparison （significance level α=0.05）. Results Of 134 air samples, 3 samples were culture-recovery, and identified respectively as M. tuberculosis, M. intracellulare and M. gordonae by gene sequencing. For BacT/ALERT 3D culture, 2 samples were conta-minated, and its culture-recovery rate was 2.3% （3/132）. For L-J culture, 1 sample was contaminated, and its culture-recovery rate was 1.5% （2/133）. There was no significant difference between these two methods （χ2=0.00,P〉0.05）. Conclusion Mycobacterium existed in the wards of sputum smear-positive TB inpatient in TB hospital. Surveying termly the air of TB hospital is an important measure to prevent and control the nosocomial infection.