Mycobacterium avium resists exposure to the acidic conditions of the stomach.
Mycobacterium avium resists exposure to the acidic conditions of the stomach.
复制标题
鸟分枝杆菌可以抵抗胃的酸性条件。
DOI：
10.1111/j.1574-6968.2000.tb08871.x
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发表时间：
2000
影响因子：
2.1
通讯作者：
Bermudez,LE
中科院分区：
文献类型：
--
作者：
Bodmer,T;Miltner,E;Bermudez,LE
禽分枝杆菌复合体是免疫抑制患者(如艾滋病患者)的常见病原体。有证据表明，在艾滋病患者中，主要途径形式。禽类感染是指胃肠道。胃对病原体是一个强大的屏障，抵抗暴露在低于3的pH下的能力已被证明是肠道病原体的毒力决定因素。三株金黄色葡萄球菌临床分离株的培养。在酸性条件下，金黄色葡萄球菌表现出抗性。在pH值为2.2的条件下，菌体生长到指数期和稳定期各2小时，抑制蛋白质合成对其耐酸性没有影响。当pH值为2.2的培养时间延长到24 h时，生长到静止相的细菌对酸的耐受性显著高于指数期细菌；在有水存在的情况下，与酸孵育的航空分枝杆菌对pH 2.2的耐受性显著增强。在有缓冲液存在的情况下，使之保持稳定。在暴露在酸性条件下之前在水中预适应也与提高对PH2.2的抵抗力有关。Hank‘s平衡盐溶液的等渗性似乎与孵育2-24小时的耐酸能力减弱有关。这些发现表明，m。禽类对pH和lt；3具有天然的耐受性，预适应的条件类似于M。在环境中发现的禽类导致耐酸性增强。
Organisms of theMycobacterium aviumcomplex are common pathogens in immunosuppressed patients such as individuals with AIDS. There is evidence that in AIDS patients, the main route forM. aviuminfection is the gastrointestinal tract. The stomach is a formidable barrier to pathogens and the ability to resist exposure to pH lower than 3 has been shown to be a virulence determinant of enteric pathogens. Incubation of three clinical isolates ofM. aviumunder acidic pH revealed resistance ofM. aviumgrown both to the exponential and stationary phase at pH 2.2 for 2 h. Inhibition of protein synthesis had no effect on the acid tolerance. When the duration of the incubation at pH 2.2 was extended to 24 h, bacteria grown to the stationary phase had a significantly greater tolerance to acid than exponential phase bacteria.M. aviumincubated with acid in the presence of water was significantly more resistant to pH 2.2 thanM. aviumin the presence of buffer. Pre-adaptation in water prior to exposure to acidic conditions was also associated with increased resistance to pH 2.2. Isoosmolarity of Hank's balanced salt solution appears to be responsible for the impaired resistance to acid between 2 and 24 h of incubation. These findings indicate thatM. aviumis naturally tolerant to pH<3 and that pre-adaptation under conditions similar to the conditions whereM. aviumis found in the environment results in increased acid resistance.