Abstract：
Clostridium botulinum is a notorious pathogen that raises health and food safety concerns by producing the potent botulinum neurotoxin and causing botulism, a potentially fatal neuroparalytic disease in humans and animals. Efficient methods for the identification and isolation of C. botulinum are warranted for laboratory diagnostics of botulism and for food safety risk assessment. The cell wall binding domains (CBD) of phage lysins are recognized by their high specificity and affinity to distinct types of bacteria, which makes them promising for the development of diagnostic tools. We previously identified CBO1751, which is the first antibotulinal phage lysin showing a lytic activity against C. botulinum Group I. In this work, we assessed the host specificity of the CBD of CBO1751 and tested its feasibility as a probe for the specific isolation of C. botulinum Group I strains. We show that the CBO1751 CBD specifically binds to C. botulinum Group I sensu lato (including C. sporogenes) strains. We also demonstrate that some C. botulinum Group I strains possess an S-layer, the disruption of which by an acid glycine treatment is required for efficient binding of the CBO1751 CBD to the cells of these strains. We further developed CBO1751 CBD-based methods using flow cytometry and magnetic separation to specifically isolate viable cells of C. botulinum Group I. These methods present potential for applications in diagnostics and risk assessment in order to control the botulism hazard.
摘要：
肉毒梭状芽孢杆菌是一种臭名昭著的病原体，通过产生有效的肉毒神经毒素并引起肉毒杆菌中毒，引起健康和食品安全问题。人类和动物的一种潜在致命的神经麻痹性疾病。对于肉毒杆菌中毒的实验室诊断和食品安全风险评估，需要鉴定和分离肉毒杆菌的有效方法。噬菌体溶素的细胞壁结合域（CBD）通过其对不同类型细菌的高特异性和亲和力而被识别。这使得它们有希望开发诊断工具。我们先前鉴定了CBO1751，这是第一个显示抗肉毒杆菌I组裂解活性的抗肉毒杆菌噬菌体溶素。在这项工作中，我们评估了CBO1751的CBD的宿主特异性，并测试了其作为特异性分离肉毒杆菌I组菌株的探针的可行性。我们表明CBO1751CBD特异性结合肉毒杆菌I组（包括产孢菌）菌株。我们还证明了一些肉毒杆菌I组菌株具有S层，需要通过酸甘氨酸处理来破坏CBO1751CBD与这些菌株的细胞的有效结合。我们进一步开发了使用流式细胞术和磁性分离的基于CBO1751CBD的方法，以特异性分离肉毒杆菌I组的活细胞。这些方法具有在诊断和风险评估中应用以控制肉毒中毒危害的潜力。
