Haas W H, Amthor B, Engelmann G, Rimek D, Bremer H J
Department of General Pediatrics, Children's Hospital, University of Heidelberg, Germany.
Pediatr Infect Dis J. 1998 Nov;17(11):1016-20. doi: 10.1097/00006454-199811000-00011.
Analysis of gastric aspirates is a routine procedure for detection of Mycobacterium tuberculosis in pediatric pulmonary tuberculosis. However, identification of nontuberculous mycobacteria in gastric aspirates of immunocompetent children is not thought to be clinically significant.
A PCR method was devised for the detection of M. avium in clinical specimens. The method is based on the amplification of a M. avium-specific DNA fragment present in the 3'-end of the repetitive element IS1245. Surgically removed lymphatic tissue was analyzed prospectively by microscopy, culture and PCR in 13 children admitted to our hospital with suspected mycobacterial lymphadenitis. In 4 of these children 1 to 4 gastric aspirates were obtained before surgical treatment and submitted to the same analysis.
We report the detection of M. avium in the gastric aspirates of two children with cervical lymphadenitis before surgical intervention by a novel PCR method. The subsequently surgically removed lymph nodes were also positive by PCR and culture. In one child cultures of both sources grew M. avium. The isolates could be identified as the same strain by DNA fingerprinting. The PCR assay was almost twice as sensitive as culture in detecting M. avium.
Our findings suggest the possibility for noninvasive diagnosis of cervical lymphadenitis caused by nontuberculous mycobacteria before surgery. In addition detection of M. avium in gastric aspirates without evidence of fistula formation provides new insights into the pathogenesis of mycobacterial infection and disease in immunocompetent children.
分析胃吸出物是检测儿童肺结核中结核分枝杆菌的常规方法。然而，免疫功能正常儿童的胃吸出物中非结核分枝杆菌的鉴定在临床上被认为无显著意义。
设计了一种用于检测临床标本中鸟分枝杆菌的PCR方法。该方法基于对重复元件IS1245 3'端存在的鸟分枝杆菌特异性DNA片段进行扩增。对我院收治的13例疑似分枝杆菌性淋巴结炎的儿童手术切除的淋巴组织进行前瞻性显微镜检查、培养和PCR分析。其中4例儿童在手术治疗前获取了1至4份胃吸出物并进行相同分析。
我们报告通过一种新型PCR方法在两名颈淋巴结炎儿童手术干预前的胃吸出物中检测到鸟分枝杆菌。随后手术切除的淋巴结经PCR和培养也呈阳性。一名儿童两个来源的培养物均培养出鸟分枝杆菌。通过DNA指纹图谱可将分离株鉴定为同一菌株。在检测鸟分枝杆菌方面，PCR检测的敏感性几乎是培养的两倍。
我们的研究结果提示术前对非结核分枝杆菌引起的颈淋巴结炎进行无创诊断的可能性。此外，在无瘘管形成证据的胃吸出物中检测到鸟分枝杆菌为免疫功能正常儿童分枝杆菌感染和疾病的发病机制提供了新的见解。
