鸟分枝杆菌（MA）主要根据其生物学特性分为四个亚种 寄主范围和由MA亚种组成。鸟类，马亚种。森林（木材） 鸽子），马亚种。副结核（宿主范围广泛，定义不清）和 最近描述了马亚伯。人类（人类和猪）。MA在世界上无处不在 环境和证据表明，水可能是人类接触的一个来源。 接触水性病原体的途径包括摄入、吸入水蒸气、， 以及摄入用污染水灌溉或清洗的农产品。我们的目标是 本研究旨在确定MA亚种的特异性。人类是通过 对人类临床分离的MA进行分类，并确定MA的比例 从属于该亚种的食物和水中分离出来。理解 马亚种的出现。水和食物中的微生物将有助于美国的环境保护 保护机构在评估人类接触这些来源的风险时。 温度增长范围为1245拷贝数，16S-23S内部序列 转录间隔区或hsp65基因等方法已被用于 区分人类亚种和其他亚种。马亚伯。人类 在45℃下，可在添加丙酮酸的Lownestein-Jensen（LJ）培养基上生长 鸟类型分离物不能（Mijs等人，2002年）。临床和环境MA分离株 我们收集的样本接种在这种培养基上，并允许培养90天 天。90%的菌株在25℃下生长，67%在45℃下生长。隔离 在45℃下生长也在25℃下生长。近100%的人类分离物包括在这项研究中 这项研究在45℃下进行，表明它们是MA亚种的菌株。人类是。此外 我们对hsp65基因的3'端进行了PCR和序列分析，以此作为检测的手段 确认马亚伯。这是身份识别。人类分离株具有hsp65序列 描述了与MA亚种的hsp65序列密切相关的基因 先前此外，从环境分离物中提取了几个hsp65序列 与人类的相同或非常接近。没有一个人 我们研究中的环境分离株具有与MA亚种聚集的hsp65序列。 鸟类或副结核。这些数据表明，特定于 人类在环境中可能比以前认为的更普遍。包括6个参考文献、表格、图表。

Mycobacterium avium (MA) is divided into four subspecies based primarily on host-range and consists of MA subsp. avium (birds), MA subsp. silvaticum (wood pigeons), MA subsp. paratuberculosis (broad, poorly-defined host range), and the recently described MA subsp. hominissuis (humans and swine). MA is ubiquitous in the environment and evidence suggests water is a possible source of human exposure. Routes of exposure to waterborne pathogens include ingestion, inhalation of water vapor, and ingestion of produce irrigated or washed with contaminated water. The goal of this study was to determine the specificity of MA subsp. hominissuis to humans by subspeciating human clinical isolates of MA, and also to determine the proportion of MA isolated from food and water that belongs to this subspecies. Understanding the occurrence of MA subsp. hominissuis in water and food will aid the U.S. Environmental Protection Agency in assessing the risk of human exposure to these sources. Temperature growth range, IS1245 copy number, sequencing of the 16S-23S internal transcribed spacer region or hsp65 gene and other methods have been used to differentiate subspecies hominissuis from the other subspecies. MA subsp. hominissuis can grow on Lownestein Jensen (LJ) medium supplemented with pyruvate at 45 Cº while bird type isolates cannot (Mijs et al., 2002). Clinical and environmental MA isolates from our collection were inoculated on this medium and allowed to incubate for up to 90 days. Ninety percent of the isolates grew at 25 Cº and 67% grew at 45 Cº. Isolates that grew at 45 Cº also grew at 25 Cº. Nearly 100% of the human isolates included in this study grew at 45 Cº, suggesting they are strains of MA subsp. hominissuis. In addition, we performed PCR and sequence analysis on the 3' end of the hsp65 gene as a means to confirm MA subsp. hominissuis identification. Human isolates had hsp65 sequences closely related to hsp65 sequences from MA subspecies hominissuis described previously. Moreover, several hsp65 sequences from environmental isolates were identical or very closely related to those of hominissuis. None of the human or environmental isolates in our study had hsp65 sequences that clustered with MA subsp. avium or paratuberculosis. These data suggest that the type of MA that is specific to humans may be more prevalent in the environment than was previously thought. Includes 6 references, table, figure.