Naser Saleh A, Sagramsingh Sudesh R, Naser Abed S, Thanigachalam Saisathya
Saleh A Naser, Sudesh R Sagramsingh, Abed S Naser, Saisathya Thanigachalam, Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, Orlando, FL 32816, United States.
World J Gastroenterol. 2014 Jun 21;20(23):7403-15. doi: 10.3748/wjg.v20.i23.7403.
Crohn's disease (CD) is a chronic inflammatory condition that plagues millions all over the world. This debilitating bowel disease can start in early childhood and continue into late adulthood. Signs and symptoms are usually many and multiple tests are often required for the diagnosis and confirmation of this disease. However, little is still understood about the cause(s) of CD. As a result, several theories have been proposed over the years. One theory in particular is that Mycobacterium avium subspecies paratuberculosis (MAP) is intimately linked to the etiology of CD. This fastidious bacterium also known to cause Johne's disease in cattle has infected the intestines of animals for years. It is believed that due to the thick, waxy cell wall of MAP it is able to survive the process of pasteurization as well as chemical processes seen in irrigation purification systems. Subsequently meat, dairy products and water serve as key vehicles in the transmission of MAP infection to humans (from farm to fork) who have a genetic predisposition, thus leading to the development of CD. The challenges faced in culturing this bacterium from CD are many. Examples include its extreme slow growth, lack of cell wall, low abundance, and its mycobactin dependency. In this review article, data from 60 studies showing the detection and isolation of MAP by PCR and culture techniques have been reviewed. Although this review may not be 100% comprehensive of all studies, clearly the majority of the studies overwhelmingly and definitively support the role of MAP in at least 30%-50% of CD patients. It is very possible that lack of detection of MAP from some CD patients may be due to the absence of MAP role in these patients. The latter statement is conditional on utilization of methodology appropriate for detection of human MAP strains. Ultimately, stratification of CD and inflammatory bowel disease patients for the presence or absence of MAP is necessary for appropriate and effective treatment which may lead to a cure.
克罗恩病（CD）是一种困扰着全球数百万人的慢性炎症性疾病。这种使人衰弱的肠道疾病可始于儿童早期并持续至成年晚期。其体征和症状通常多种多样，诊断和确诊该病往往需要进行多项检查。然而，人们对CD的病因仍知之甚少。因此，多年来提出了几种理论。其中一种特别的理论是，副结核分枝杆菌（MAP）与CD的病因密切相关。这种挑剔的细菌也已知会在牛身上引起副结核病，多年来一直感染动物的肠道。据信，由于MAP厚厚的蜡质细胞壁，它能够在巴氏杀菌过程以及灌溉净化系统中的化学过程中存活下来。随后，肉类、乳制品和水成为将MAP感染传播给有遗传易感性的人类（从农场到餐桌）的关键媒介，从而导致CD的发生。从CD患者中培养这种细菌面临诸多挑战。例如，它生长极其缓慢、缺乏细胞壁、丰度低以及对分枝杆菌素具有依赖性。在这篇综述文章中，对60项通过PCR和培养技术检测和分离MAP的研究数据进行了综述。尽管这篇综述可能并未100%涵盖所有研究，但显然大多数研究压倒性地明确支持MAP在至少30% - 50%的CD患者中所起的作用。某些CD患者未检测到MAP很可能是因为这些患者中不存在MAP的作用。后一种说法取决于是否采用了适用于检测人类MAP菌株的方法。最终，对CD和炎症性肠病患者进行MAP存在与否的分层，对于可能导致治愈的恰当有效治疗是必要的。
