Warren Robin M, Victor Thomas C, Streicher Elizabeth M, Richardson Madalene, Beyers Nulda, Gey van Pittius Nicolaas C, van Helden Paul D
Medical Research Council Centre for Molecular and Cellular Biology, Department of Medical Biochemistry, Stellenbosch University, Tygerberg, South Africa.
Am J Respir Crit Care Med. 2004 Mar 1;169(5):610-4. doi: 10.1164/rccm.200305-714OC. Epub 2003 Dec 30.
It is generally accepted that tuberculosis results from a single infection with a single Mycobacterium tuberculosis strain. Such infections are thought to confer protective immunity against exogenous reinfection. In this study, a novel polymerase chain reaction method was developed to specifically identify M. tuberculosis strains belonging to the Beijing and non-Beijing evolutionary lineages in sputum specimens collected from tuberculosis patients resident in an epidemiologic field site in Cape Town, South Africa. The sensitivity and specificity of the polymerase chain reaction-based strain classification method were 100% (95% confidence interval, 85-100%) when compared with DNA fingerprinting and spacer oligotyping (spoligotyping). Application of this method showed that 19% of all patients were simultaneously infected with Beijing and non-Beijing strains, and 57% of patients infected with a Beijing strain were also infected with a non-Beijing strain. Multiple infections were more frequent in retreatment cases (23%) as compared with new cases (17%), but were not associated with sex, age, or smear grading. These results suggest that multiple infections are frequent, implying high reinfection rates and the absence of efficient protective immunity conferred by the initial infection. This finding could influence our understanding of the epidemiology of disease in high-incidence regions and our understanding for vaccine development.
一般认为，结核病是由单一结核分枝杆菌菌株的单次感染引起的。这种感染被认为可赋予针对外源性再感染的保护性免疫。在本研究中，开发了一种新型聚合酶链反应方法，以特异性鉴定从南非开普敦一个流行病学现场的结核病患者收集的痰标本中属于北京和非北京进化谱系的结核分枝杆菌菌株。与DNA指纹图谱和间隔寡核苷酸分型（spoligotyping）相比，基于聚合酶链反应的菌株分类方法的敏感性和特异性为100%（95%置信区间，85-100%）。应用该方法显示，所有患者中有19%同时感染了北京和非北京菌株，感染北京菌株的患者中有57%也感染了非北京菌株。与新发病例（17%）相比，复治病例中多重感染更为常见（23%），但与性别、年龄或涂片分级无关。这些结果表明多重感染很常见，这意味着再感染率高，且初始感染未赋予有效的保护性免疫。这一发现可能会影响我们对高发病率地区疾病流行病学的理解以及对疫苗开发的理解。
