School of Pharmacy and Pharmaceutical Sciences, Cardiff University, Cardiff, United Kingdom.
Appl Environ Microbiol. 2012 Nov;78(21):7671-9. doi: 10.1128/AEM.01862-12. Epub 2012 Aug 24.
Clostridium difficile is the commonest cause of hospital-acquired infection in the United Kingdom. We characterized the abilities of 21 clinical isolates to form spores; to adhere to inorganic and organic surfaces, including stainless steel and human adenocarcinoma cells; and to germinate. The composition of culture media had a significant effect on spore formation, as significantly more spores were produced in brain heart infusion broth (Student's t test; P = 0.018). The spore surface relative hydrophobicity (RH) varied markedly (14 to 77%) and was correlated with the ability to adhere to stainless steel. We observed no correlation between the ribotype and the ability to adhere to steel. When the binding of hydrophobic (DS1813; ribotype 027; RH, 77%) and hydrophilic (DS1748; ribotype 002; RH, 14%) spores to human gut epithelial cells at different stages of cell development was examined, DS1813 spores adhered more strongly, suggesting the presence of surface properties that aid attachment to human cells. Electron microscopy studies revealed the presence of an exosporium surrounding DS1813 spores that was absent from spores of DS1748. Finally, the ability of spores to germinate was found to be strain and medium dependent. While the significance of these findings to the disease process has yet to be determined, this study has highlighted the importance of analyzing multiple isolates when attempting to characterize the behavior of a bacterial species.
艰难梭菌是英国最常见的医院获得性感染病原体。我们对 21 株临床分离株的形成孢子的能力、黏附无机和有机表面（包括不锈钢和人腺癌细胞）的能力和萌发的能力进行了研究。培养基的组成对孢子形成有显著影响，脑心浸液肉汤中产生的孢子明显更多（Student's t 检验；P = 0.018）。孢子表面相对疏水性（RH）差异显著（14%至 77%），与黏附不锈钢的能力相关。我们没有观察到核糖体类型与黏附钢的能力之间存在相关性。当观察不同细胞发育阶段疏水（DS1813；核糖体类型 027；RH，77%）和亲水（DS1748；核糖体类型 002；RH，14%）孢子与人肠道上皮细胞结合时，DS1813 孢子的结合更紧密，这表明其表面存在有助于与人类细胞附着的特性。电子显微镜研究显示，DS1813 孢子周围存在外孢子，而 DS1748 孢子则没有。最后，发现孢子的萌发能力取决于菌株和培养基。虽然这些发现对疾病过程的意义尚未确定，但本研究强调了在试图描述细菌物种的行为时，分析多个分离株的重要性。
